Use bzero to clear SquirrelUIStyle struct.
Fix initial alpha value for last commit.
squirrel.yaml: new option 'style/line_spacing:'
register and enable input source by calling `Squirrel --install`.
Merge remote-tracking branch 'upstream/master'

* upstream/master:
  register and enable input source by calling `Squirrel --install`.
  squirrel.yaml: new option 'style/line_spacing:'
  Fix initial alpha value for last commit.
  Use bzero to clear SquirrelUIStyle struct.

Conflicts:
	SquirrelApplicationDelegate.m
	SquirrelPanel.h
	SquirrelPanel.m
	data/squirrel.yaml