push end_play exceptions down one level in playsingle_controller

This uses the macros introduced to handle game end exceptions.
It should be a strict refactor.

Rebased to accomodate conflict here: 516206a
Still a strict refactor.

Note:
If end_turn_exception propogates to the top of
playsingle_controller, there is no handler beyond that and the
program will terminate. If an end turn signal gets there, we
also will terminate. This commit adds an assertion failure with
a message clarifying what happened.