Took the null texture and null animations out of the map and made them global variables. Why bother looking something up in a map when its certain to exist? This also allows us to stop using [] with the map and thereby eliminate the need for default constructors of map contents.
Removed hardcoding of res/ directory. To compensate, added a system for finding image files relative to the texture-list file.
Changed to using a simple boolean to indicate the direction of an animation's frames (instead of using 'h' and 'v' characters)