This commit changes the replica path format to group segments within
a single index in the same directory. This is to eventually add the
ability to seek to a record on file-based systems without having
to iterate over the records. The DB shadow WAL will also be changed
to this same format to support live replicas.

Per the godoc on Replica.Restore and RestoreOptions.OutputPath,
Replica.db.path should be used when RestoreOptions.OutputPath is empty.

Fixes benbjohnson#233

This commit fixes an issue where the reference is taken
on the loop variable rather than the slice element when
computing the minimum snapshot within a generation so
it can cause the wrong snapshot to be chosen.

By default, the snapshots command seems to output in alphabetical order of hash, which isn't meaningful, as far as I can tell.

This change modifies the order of the command output so that ./litestream snapshots returns snapshots from newest to oldest.

This commit refactors out the complexity of downloading ordered WAL
files in parallel to a type called `WALDownloader`. This makes it
easier to test the restore separately from the download.

Bumps [github.com/pierrec/lz4/v4](https://github.com/pierrec/lz4) from 4.1.3 to 4.1.12.
- [Release notes](https://github.com/pierrec/lz4/releases)
- [Commits](pierrec/lz4@v4.1.3...v4.1.12)

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updated-dependencies:
- dependency-name: github.com/pierrec/lz4/v4
  dependency-type: direct:production
  update-type: version-update:semver-patch
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Bumps [github.com/aws/aws-sdk-go](https://github.com/aws/aws-sdk-go) from 1.27.0 to 1.42.39.
- [Release notes](https://github.com/aws/aws-sdk-go/releases)
- [Changelog](https://github.com/aws/aws-sdk-go/blob/main/CHANGELOG.md)
- [Commits](aws/aws-sdk-go@v1.27.0...v1.42.39)

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  dependency-type: direct:production
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Bumps [cloud.google.com/go/storage](https://github.com/googleapis/google-cloud-go) from 1.15.0 to 1.18.2.
- [Release notes](https://github.com/googleapis/google-cloud-go/releases)
- [Changelog](https://github.com/googleapis/google-cloud-go/blob/main/CHANGES.md)
- [Commits](googleapis/google-cloud-go@pubsub/v1.15.0...storage/v1.18.2)

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Bumps [google.golang.org/api](https://github.com/googleapis/google-api-go-client) from 0.45.0 to 0.65.0.
- [Release notes](https://github.com/googleapis/google-api-go-client/releases)
- [Changelog](https://github.com/googleapis/google-api-go-client/blob/main/CHANGES.md)
- [Commits](googleapis/google-api-go-client@v0.45.0...v0.65.0)

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Bumps [github.com/aws/aws-sdk-go](https://github.com/aws/aws-sdk-go) from 1.42.39 to 1.42.40.
- [Release notes](https://github.com/aws/aws-sdk-go/releases)
- [Changelog](https://github.com/aws/aws-sdk-go/blob/main/CHANGELOG.md)
- [Commits](aws/aws-sdk-go@v1.42.39...v1.42.40)

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  dependency-type: direct:production
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Previously, Litestream would avoid closing the SQLite3 connection
in order to ensure that the WAL file was not cleaned up by the
database if it was the last connection. This commit changes the
behavior by introducing a file control call to perform the same
action. This allows us to close the database file normally in all
cases.

This reverts commit 26f219d.

Bumps [github.com/aws/aws-sdk-go](https://github.com/aws/aws-sdk-go) from 1.42.40 to 1.42.44.
- [Release notes](https://github.com/aws/aws-sdk-go/releases)
- [Changelog](https://github.com/aws/aws-sdk-go/blob/main/CHANGELOG.md)
- [Commits](aws/aws-sdk-go@v1.42.40...v1.42.44)

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  dependency-type: direct:production
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Bumps [google.golang.org/api](https://github.com/googleapis/google-api-go-client) from 0.65.0 to 0.66.0.
- [Release notes](https://github.com/googleapis/google-api-go-client/releases)
- [Changelog](https://github.com/googleapis/google-api-go-client/blob/main/CHANGES.md)
- [Commits](googleapis/google-api-go-client@v0.65.0...v0.66.0)

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Bumps [cloud.google.com/go/storage](https://github.com/googleapis/google-cloud-go) from 1.18.2 to 1.19.0.
- [Release notes](https://github.com/googleapis/google-cloud-go/releases)
- [Changelog](https://github.com/googleapis/google-cloud-go/blob/main/CHANGES.md)
- [Commits](googleapis/google-cloud-go@storage/v1.18.2...spanner/v1.19.0)

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Bumps [github.com/prometheus/client_golang](https://github.com/prometheus/client_golang) from 1.12.0 to 1.12.1.
- [Release notes](https://github.com/prometheus/client_golang/releases)
- [Changelog](https://github.com/prometheus/client_golang/blob/main/CHANGELOG.md)
- [Commits](prometheus/client_golang@v1.12.0...v1.12.1)

---
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  dependency-type: direct:production
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This commit removes the shadow WAL iterator and replaces it with a
fileWalSegmentIterator instead. This works since the shadow WAL now
has the same structure as the replica WAL. This reduces duplicate
code and will make it so read replication can be daisy chained in
the future.

Unfortunately, I don't have the expertise or bandwidth to maintain
the Windows support in Litestream. I'm open to re-adding support in
the future but right now it is hindering development and is not
well-tested or well-used.

Previously, Litestream had a validator that worked most of the time
but also caused some false positives. It is difficult to provide
validation from with Litestream without controlling outside processes
that can also affect the database. As such, validation has been moved
out to the external CI test runner which provides a more consistent
validation process.

Under high write load, it is possible for write transactions from
another process to overrun the WAL between the time when Litestream
performs a RESTART checkpoint and when it obtains the write lock
immediately after. This change adds validation that an overrun has
not occurred and, if it has, it will start a new generation.

- github.com/aws/aws-sdk-go v1.42.44 => v1.42.48
- cloud.google.com/go/storage v1.19.0 => v1.20.0
- github.com/pierrec/lz4/v4 v4.1.12 => v4.1.14
- google.golang.org/api v0.66.0 => v0.67.0

Previously, the index & offsets were encoded as 8-character hex
strings, however, this limits the maximum value to a `uint32`. This
is normally not an issue, however, indices could go over the maximum
value of 4 billion over time and the offset could exceed this value
for an especially large WAL update. For safety, these encodings have
been updated to 16-character hex encodings.

Currently, WALSegmentIterator implementations read to the end of
the end of their list of segments and return EOF. This commit adds
the ability to push additional segments to in-process iterators and
notify their callers that new segments are available. This is only
implemented for the file-based iterator but other segment iterators
may get this implementation in the future or have a wrapping
iterator provide a polling-based implementation.

Co-authored-by: Ben Johnson <benbjohnson@yahoo.com>

The `monitor-delay-interval` has been added to the DB config so that
users can change the time period between WAL checks after a file
change notification has occurred. This can be useful to batch up
changes in larger files in the shadow WAL or to reduce or eliminate
the delay in propagating changes during read replication.

Setting the interval to zero or less will disable it.

This commit adds an http server and client for streaming snapshots
and WAL pages from an upstream Litestream primary to a read-only
replica.

export LITESTREAM_ACCESS_KEY_ID=your_key_id
export LITESTREAM_SECRET_ACCESS_KEY=your_access_key
export LITESTREAM_ENDPOINT=your_endpoint
export LITESTREAM_REGION=your_region
litestream replicate fruits.db s3://mybkt/fruits.db

Signed-off-by: Ryan Russell <ryanrussell@users.noreply.github.com>

Signed-off-by: Ryan Russell <git@ryanrussell.org>