[frontend/termbox] Cache the caret style.

This reverts a change that looks accidental, but might be intentional...
[frontend] Silence govet.

Add log.Errorf.
[backend] Start resolving govet issues.
[backend] Resolve more govet issues.
[backend/log] Move the log tests into the log package.
Merge branch 'master' of github.com:limetext/lime into move_command

* 'master' of github.com:limetext/lime:
  [backend/log] Move the log tests into the log package.
  [backend] Resolve more govet issues.
  [backend] Start resolving govet issues.
  [frontend] Silence govet.
  [frontend/termbox] Cache the caret style.
Removed repeated test also added some comments
Implemented move by words
Implemented Move by WordEnds
Implemented move by subwords & subword_ends