Exclude tools, data and data-dependent tests/benches in packages

[behnam]

We should use the Cargo exclude option to not publish data files to crates.io, as they are usually very large and almost of no use for 99.99% of the callers.

See servo/unicode-bidi#43 for report issue with publishing tests without data when published crate is being used in repackaging.

See also rust-lang/cargo#4268 for current limits of the exclude syntax, and the changes coming.

[CAD97]

Is there a way to dry-run cargo publish?

Without being able to test it, this might work (though since (I think) exclude doesn't get inherited it would have to be applied to all packages):

exclude = ["data/**/*", "src/**/tests/*conformance*.rs"]

[behnam]

cargo package creates the .crate file, which is what gets uploaded to crates.io, and downloaded later for consumption. The output is saved as target/package/<package-name>-<package-version>.crate.