Add chat box for command feedback and future chatting. Update commands.

- Add a larger, readonly "chat box" above the text input to display
  results of commands, errors, and user chat. This box is scrollable
  with the mouse wheel.

- GiveBlockCommand updates inventory/item list so that changes appear
  even if the inventory is already open.

- Add convenience method item.get_item which looks up the actual item
  instance for a given block/item id.

- Simplify resizing by taking it out of Control and forget attempting
  to write an anchoring algorithm

- Make Control a pyglet EventDispatcher to follow event conventions

- Use ChunkFive Roman font
Merge branch 'master' into chat-box

Conflicts:
	controllers.py
	gui.py
	inventory.py
	items.py
Make TextWidget font name configurable

- Use Arial for chat boxes.

- Use G.FONT_DEFAULT by default.
Add a HelpCommand to print out help_text of all commands.
Merge branch 'master' of https://github.com/boskee/Minecraft
Merge branch 'master' of https://github.com/boskee/Minecraft
Merge remote-tracking branch 'boskee/master'

Conflicts:
	commands.py
	items.py
Hide text inputs from TakeScreenCapCommand, and echo the save path