Make drags cancellable by pressing escape
- Sometimes doesn't work?
Rebuild
Trying to fix up merge with master
Experimented with music block colour and some bug fixes.
Initial "recent gists" submenu

Not completely functional
Initial skeleton of an undo/redo system
Add undo and redo to the context menu and make cut/copy/paste undoable/redoable.
Implement undo/redo for dragging, not yet fully functional
Merge branch 'master' into 250_undoredo
Merge branch 'master' into canceldrag

Conflicts:
	dist/arduino.js
	dist/javascript.js
	dist/minecraftjs.js
Cancelling the drag now works reliably!
Rebuild
Show/hide block menus

Not persistent
Merge pull request #376 from CelticMinstrel/canceldrag

Allow a drag to be cancelled by pressing Escape while dragging
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
Use built-in element.classList functions
Merge pull request #379 from dannywils/master

Use built-in element.classList functions