moved heuristic constants to static member in bot_ali and other changes
Merge branch 'master' into develop

Conflicts:
	src/main/squared.cpp
bug in board::walk_diff
removed forgotten hash table lines
changed discs[2] in board to me and opp bitsets, removed WHITE,BLACK constants
small changes
fixed bug in board::get_valid_moves()
repaired non-working bot
fixed bug in bot_ali::do_move(), added OPTIMIZED_DEBUG_FLAGS in src/CMakeLists.txt