Various improvements and fixes

Improvements:
Sunfish now handles check, and checkmate, as well as stalemate
Sunfish is slightly more selective
Sunfish has the xboard-friendly-ish

Bugs:
X B o a r d - f r i e n d l y - i s h o u t p u t h a s a l o t of m e a
n i n g l e s s s p a c e s