Reset the crate contents (sources, tests, etc.)
to what they were at that commit, while retaining the newer CI
configuration.
The changes since the 0.22.0 release were primarily intended to
accomplish two goals:
* Fix and improve the GitHub Actions configuration.
* Prepare a 0.21.5 release that was backward compatible with 0.21.4
but which also contained the improvements that were in 0.22.0.
0.21.5 was never released and will not be released. Therefore all
of the noise to facilitate the 0.21.5 release can just be deleted,
as long as we leave the CI changes that are necessary for GitHub
Actions to work correctly now.
The exact commands I used were:
```
git checkout \
6c334a2cf5 \
-- \
Cargo.toml \
LICENSE \
README.md \
src \
tests \
third-party
git rm src/trust_anchor_util.rs
```
Commit 6c334a2cf5 was the commit from
which 0.22.0 was released. It is confusing because the commit
immediately prior, 0b7cbf2d32, has
commit message "0.22.0". It appears that I merged the "0.22.0"
commit, expecting to `cargo publish` from that commit, but then
`cargo publish` failed. Then I added
6c334a2cf5 to fix `cargo publish`
and did the `cargo publish` from that commit. That's why I added
the `package` CI step at that time, to prevent this confusing
situation from happening again.
`trust_anchor_utils.rs` was not in 0.22.0; the `git checkout` didn't
delete it, so I had to do it separately.
I left the tests added subsequent to 0.22.0 in `tests/` (e.g.
`name_tests.rs`) since those tests pass with the 0.22.0 sources too.
Unfortunately, this requires disabling a bunch of Clippy lints, to
avoid modifying the contents from 0.22.0.
(I know it is confusing. It took me a while to figure it out myself
today.)
Test all feature configurations in CI.
Remove the `trust_anchor_utils` feature flag.
Guard all features that directly require allocation with a new `alloc` feature.
The RSA features will be handled separately.
Document the features. Tell docs.rs to document all features.
Adjust some tests so that tests are run in more configurations.