Fix a crash when quitting with F10 mid-IP combat.

The Lua state object was destroyed before returning to the main
menu, but the main menu checks the state to see how to transition
in (mostly involving the Utwig bomb).

I've fixed it by modifying the Lua state lifecycle slightly. This
also replaces asserts with console log warnings.
Fix several save/gamestate corruption bugs

Multibit gamestate reads that were not an integral number of bytes and which
crossed byte boundaries in the game state array would incorrectly shift
high bits, producing incorrect state values at load time.

One constant sent to GET_GAME_STATE did not correspond to any existent state
due to a typo. A systematic code search found no further instances of this
outside of #ifdef NEVER blocks (the DATA_PLATE related game states).
Building with internal LUA requires libm