Some more changes

Adds some needed accessors into BiMap, big change to stateMachine, and
some additions to GUIF.
-screen property, returns a rect that is the screen. get only.
-GUIStyleF - A few nifty extension functions to derive a new style from
a previous style, changing the alignment or text size. Chainable.
-RectF - added a few more useful functions, Aspect scales the width of a
Rect based on its height and proportion.
Added functions for taking 'slices' of the Rect (Top instead of TopLeft,
automatically returns the same width of the Rect)