* General Cargo.toml cleanup.
- Remove travis-ci attributes.
- Remove "experimental" badges from actively-developed crates.
- Reflow some long lines.
- Use dependency features consistently.
- Add readme attributes
* Update WASI to the latest trunk.
This notably adds a .gitignore file for the WASI directory.
* Refactor Lightbeam's tests.
This refactors Lightbeam's tests.rs file into several pieces, separating
quickcheck tests into their own file, and moving tests which can be run as
wast tests into `tests/misc_testsuite`, and creating a tests directory
for the rest.
* Remove the old filetests tests.
These are all covered by misc_testsuite and spec_testsuite tests.
* rustfmt
* Remove the "bench" feature.
