refactoring of zipdir.py
bug fixed: sometimes a restored game would stay frozen at the time of the save

This is caused by the fact that the interface and the simulation are in different threads.
The simulation is waiting for a lost "update" command or has sent a lost "voila" command.

(cherry picked from commit e6d8b24661efa96529fa18afa8cdc566ffc701ab)

Conflicts:
	soundrts/game.py
added Spanish translation of the AI making manual and the modding manual

(thanks to Claudio of tiflo juegos)

(cherry picked from commit 196af30b5caf145597629ca3ca815e6d453fcf4a)