Always clear the background to hide pre-draw
TextZone: Use default font and offset words
ButtonZone: Use default font if none provided
KeyboardZone cleanup

Removes the ugly links to keyListener Zones

Automatically adds any real children Zones of the KeyboardZone as
KeyListeners

Lets ButtonZone take care of the fonts

Removes the convience method for removing a Zone key listener as it is
done automatically and should have been removed when the add zone key
listener convience method was.