Removed unnecessary type definition.
Refactored ShaderProgramMap to use Hash over std::map.
Refactored TextureUnitMap to use Hash over std::map.
Refactored TextureMap to use Hash over std::map.
Refactored ResourceProcessorMap to use Hash over std::map.
Refactored TextureAtlas to use Hash over std::map.
Refactored UniformBufferElements to use Hash over std::map.
Removed some <map> includes I'd forgotten about.