Patch 0.5.1 for the demo

Heya paper plane throwers! Here the patch notes for the first demo patch: - fixed some typos - the bestiary pages containing enemies not included in the demo now have their own page number - completing level 10 will now show the demo end screen instead of locking the game - fixed error messages for both players when launching attacks that can't be afforded or are blocked by already existing catapults I'm still working on the overlay fix. Keep inviting Your friends in the main menu ;) Happy hunting! - Mike