Initial "recent gists" submenu

Not completely functional
Show/hide block menus

Not persistent
Add saving to block prefs

Preferences are saved to localstorage
Merge branch 'wb/master'

Conflicts:
	dist/arduino.js
	dist/demo.js
	dist/javascript.js
	dist/minecraftjs.js
	scripts/workspace.js
Rebuild
Merge pull request #378 from dannywils/master

Merge block preferences