Renamed AttributeUsage and AttributeType

... to VertexComponent and ComponentType.

-Renderer:
Renamed IsVertexAttributeSupported static method to
IsComponentTypeSupported

-VertexDeclaration:
Added IsTypeSupported static method
Renamed [Disable|Enable|Get]Attribute to [Disable|Enable|Get]Component
Removed GetAttributeSize static method

-VertexMapper:
Renamed GetAttributePtr method to GetComponentPtr