Add xml comments. Centralize the dotnet target framework (#143)

Bump Version to 3.1.1 (#136)

A round of library version updates (#131)

Changes: https://libzip.org/news/release-1.10.0.html
Changes: https://libzip.org/news/release-1.10.1.html
Changes: https://zlib.net/ChangeLog.txt
Changes: https://github.com/facebook/zstd/releases/tag/v1.5.4
Changes: https://github.com/facebook/zstd/releases/tag/v1.5.5

  * libzip updated to v1.10.1 (from v1.9.2 via 1.10.0)
    A handful of API changes not important to us, fixes for handling
    very large ZIP archives and buffers, use ISO C secure library
    functions.
  * zlib updated to v1.3.0 (from v1.2.13)
    Changes which mostly affect the gzip compression, not used by
    libzip.
  * zstd updated to v1.5.5 (from v1.5.2, via v1.5.4)
    v1.5.4 is mostly a performance improvement release, see the URL
    above for details. v1.5.5 is a quickfix release addressing a
    rare corruption bug in high compression mode, plus more performance
    improvements.

Add back netcoreapp3.1 (#129)

Restore support (plus tests) for the `netcoreapp3.1` target framework.

Updates to match new libzip version + potential fix (#125)

* [WIP] Updates for the newer libzip version

Also some additions to the API as well as fixed a handful of compile
warnings

* Possible fix for the "unable to open as zip archive" error

Let's see if it breaks any tests...

* Bump version to 2.1.0

New minor version because of the new versions of native libraries

Bump version to 2.0.7

Update libzip and zlib submodules (#115)

Context: https://libzip.org/news/release-1.9.0.html
Context: https://libzip.org/news/release-1.9.1.html
Context: https://libzip.org/news/release-1.9.2.html
Context: https://zlib.net/ChangeLog.txt

`libzip` updated to v1.9.2, changes:

   * Add zip_file_is_seekable().
   * Improve compatibility with WinAES.
   * Fix encoding handling in zip_name_locate().
   * Add option to zipcmp to output summary of changes.
   * Various bug fixes and documentation improvements.

`zlib` updated to v1.2.12, changes:

   * Fix a deflate bug when using the Z_FIXED strategy that can result
     in out-of-bound accesses.
   * Fix a deflate bug when the window is full in deflate_stored().
   * Speed up CRC-32 computations by a factor of 1.5 to 3.
   * Use the hardware CRC-32 instruction on ARMv8 processors.
   * Speed up crc32_combine() with powers of x tables.
   * Add crc32_combine_gen() and crc32_combine_op() for fast combines

Bump Mono.Unix to 7.1.0-final.1.21458.1 (#110)

It fixes `libc` p/invokes on Unix.  The previous version would try to
resolve them in the `msvcrt` library instead of `libc`

Bump Version to 2.0.4 for Release (#109)

Use RuntimeInformation to determine the Processor architecture. (#108)

See https://docs.microsoft.com/en-us/dotnet/api/system.runtime.interopservices.architecture?view=net-6.0

Now that we ship an arm based native library on windows we need to be
able to determine the underlying library to load. We can use the
`RuntimeInformation.ProcessArchitecture` value to get this data.

Then based on that we can load from `x86`, `x64` or `arm64` subdirectories.
Note we will still fallback to loading from the current directory , but
the preference is to load from on of the architecture specific sub directories.