General code cleanup

Added some invalid ID protection to the HUDRegistry, added a logger to
the main class, transitioned savecontroller to use this logger.
Implemented rotation...

... on most vanilla items. Some do not have rotation states yet, but
will.
Added GuiButtonIconGrid

For things like icon selection (crosshair selection)
Add rotateWidgets.png

Used in hotbar rotation state because the vanilla texture is missing
it's bottom piece
Update reposition screen
Add crosshair-specific icon selection
Update config screen

Can now press F1 to toggle the help at the top.
Update RenderAssist

Adds some new useful methods (filled/unfilled circles, filled/unfilled
rectangles)