FLOE-135: keyboard nav for controls buttons

Added the bold, italic, and underline controls to the tab order and made them keyboard activatable.
FLOE-135: Added keyboard shortcuts

Added the keyboard short cuts for the bold, italic, and underline controls. They use the standard short cut combinations including using ctrl for windows and command for mac.
Merge branch 'master' into FLOE-135
FLOE-135: Switched progressive checking strategy

Switched to use progressiveCheckerForComponents strategy for switching between mac and pc keyboard shortcuts.
Merge remote-tracking branch 'justin/FLOE-135'

* justin/FLOE-135:
  FLOE-135: Switched progressive checking strategy
  FLOE-135: Added keyboard shortcuts
  FLOE-135: keyboard nav for controls buttons