Resources are now created with parameters

After a resource is created it can be retrieved via get. If a resource has already been created that resource
is returned on subsequent calls to create.
Renamed ResourceSsytem to ResourceSystem
Renamed GLSLShader to Shader and moved it into the resource namespace
Changed how resources are defined

Now a resource must inherit from ResourceBase, and then you must call ResourceSystem::Register<MyType>(); to make the factory method available.