Add Package Control docs.

First cut at ST3 compatibility

Configure logging level

Update reloading for Python 3

Add ST3 compatible imports

Use logging for console output

Add key binding support.

Add plugin settings to main menu.

Add a debug setting.

Neatly format command arguments.

Format keyboard shortcuts

Handle selection of key binding entry.

Show activity in status bar.

Move key binding extraction to background thread

Factor out references to UI modules