Fixed sample code.

Dealt with the LumiGeek.begin() deprecation.  Removed multi-channel sample code that was remnant from the copy-and-paste of the 4xRGB sample code.
Fixed initialization code and inherited methods.

Moved blackout() and testPattern() from protected to public.   Rearranged the begin() code.
Changed the delay after 4x calls to 8ms from 5ms.
Deprecated LumiGeek.begin() in favor of individual shield begin() calls.