Prod gitignore a bit.

Ignore FreeBSD core dumps, and ignore the correct binary name.
Clean up AudioSink a bit.

Rework control flow, and fix some ClangFormat-borked comments.
Remove useless temporary variable.
Rename PS include guards to PLAYD.
Use emplace_back, not push_back.
Check device ID before creating IoCore.

This stops the network error from happening before any ID errors.
Replace state strings map with array.

For performance reasons, mainly.  There is no reason why this needs to be a hashmap.
Update PlayerState::List comment.
Move RESPONSES to ResponseSink::STRINGS.
Make some string-table tweaks.
Clang-format everything.
Experiment with some new clang-format directives.

As per what @LordAro said in the #60 prq, mostly.
Merge pull request #61 from UniversityRadioYork/mw-more-cleanup-bis

More random cleanups (attempt 2)