remove outproc for hh
Summary:
This diff...
1. Removes HhOutproc. We felt that outproc was a burden, not a benefit
2. Simplifies the "hh_api::Hh" trait into something simpler, now that it doesn't have to support outproc.
3. Switches from thiserror to anyhow
4. Including, switch to callback instead of iterator for incremental output.
5. Regularizes hh.rs, the main binary
6. Moves hh tests from src/facebook/hh/lib/test.rs to test/facebook/hh/update.rs
7. Simplified the test code, and changed it all to return anyhow rather than panic
8. Now that the code is shorter and simpler, it's short enough to fit hh/api and hh/lib into single files. So I did that.
Reviewed By: zhyty
Differential Revision:
D40456166
fbshipit-source-id:
8048222f37929b52b164f418a39e28fababb8c52