Made AnimatedSprite subclassable
Added virtual destructor to AnimatedSprite
Added implementation of AnimatedSprite v destructor
Adding sprite with support for palettes
Using paletted sprite in Entity
Adding paletted sprite to build
Added palette swapping
Updated objects for palette swapping
Fixed initialization order bug with statics

Fixes a crash due to destructor order.
Merge pull request #123 from zackthehuman/master

Added paletted sprites; still WIP