board: use fromstr for initial board

Also add asserts errywhere
board: inCheck: first check against all_mask
make_tests: add milliseconds for opponent

This sucks, fix it
Makefile: remove -lm and add -flto=4 and -fwhole-program
addon: trivial: faster score

And more asserts
addon: killer: correctness
succs: genSuccs: simpl.
ai: genSuccs: split shuffling into shuffle_succs