Steam trading cards, extra music tracks, performance improvements, and fixes. — Enemy Steam update #419341

Hello everyone! This is just a brief announcement to sum up the changes that I've made this past month. I've been pretty heavily focused on fixes, performance, and stability, but there's also some new music and some new ambient sounds, along with Steam cards and badges. Version 1.03 4/9/2015 Add Steam trading cards. Add lots of optimizations to visibility algorithms. Handle non-ASCII characters in the user's documents directory. Fix: characters take fall damage when they pick up a floating special block. Fix: fix bug where characters could be launched into the sky and then get stuck there. Fix: ambient sounds transition correctly. Fix: when a character is melee attacked and pushed off a cliff, they would snap back onto the cliff. The region of morale damage around an attack is now spherical rather than a cube. Slightly reduce the variability in the amount of morale damage. Version 1.02 4...