Hardware Skinning Support

- Supports GL, D3D9 & D3D11
- Extends vertex formats & shadergen to support blend indices and weights
- Adds basic support for using 4x3 matrices for shader constants
- Supports software fallback

Engine/source/shaderGen/shaderComp.h

@@ -71,6 +71,8 @@ protected:
    Vector <Var*> mElementList;
 
    U32 mCurTexElem;
+   U32 mCurBlendIndicesElem;
+   U32 mCurBlendWeightsElem;
    U8 mName[32];
 
 public:
@@ -78,6 +80,8 @@ public:
    ShaderConnector();
    virtual ~ShaderConnector();
 
+   U32 getCurTexElem() { return mCurTexElem; }
+
    ///
    virtual Var* getElement(   RegisterType type, 
                               U32 numElements = 1,