OneLife

Added note about how to run the game when building from source.

Back down to 40.

Found true cause of disconnecting-held-baby-while-walking crash (pending messages playing back later, after they are dead). Fixed a few uninitialized values found with Valgrind.

Fixed a crash if held baby does not exist anymore, perhaps due to disconnect.

With the server load fixes, seems safe to push population cap up to 60.