SmartMatrix on 4 panels

Added support for 4 panels. 
• Demos include a 4 panel row (32 rows x 128 columns) and a 4 panel square (64x64). 
• Graphics, scroll text, and bitmaps work. 

Limitations:
• Rotation is not yet correct.  
• Coordinate conversion from drawing to hardware should be correct for a column layout (128 rows x 32 columns), but it has not been tested.