Update 0.44

This took a long time, and it's a rather boring update from your point of view. There are likely weird new bugs too.

• Huge rewrite of game code in preparation for the multi-player.

• Switched to FMOD sound engine.

• Game simulation and rendering are in different threads now, resulting in smoother frame rate.

• Some parts of game code were optimized to use multi-threading.

• Spells are now scripted, so potentially mod-able.

• Global resources are removed for now, so no crafting, you find spells directly in story mode.

• Gatherers and birds are not animated for now.

• Some minor features are missing for now.