* doc/org/tut40.org: Add more explanations and some cleanup.
* python/spot/__init__.py (set_state_players, get_state_winners,
get_state_players, set_state_player, get_state_winner,
get_state_player, get_strategy): Add these methods to the twa_graph
class for convenience.
* NEWS, doc/org/tut.org: Mention tut40.org.
* doc/org/tut40.org: Add a documentation on how to use games in a
pratical case. In this example, we compute simulation using
games. Fixes#445.
* doc/Makefile.am: Add tut40.org.