Added stub for board_rotate_90 in board.c. Reverted some broken test.c code.
Added 2x2 test code to test.c. Fails new tests as expected.
Added 3x3 board roate test to test.c.
Added board_rotate_180 code stub to board.c, also defined in headder.
Added some 2x2 and 3x3 tests to test.c. Still only testing stubs in board.c