Updated and corrected GLSL330 shaders. Now they are all working.

* Change LightingShader: the class doesn't inherit from ofShader anymore,
  but keeps a private pointer. May be unnecessary though
Add support to GLSL330 Blinn-Phong pixel shader for texturing (monotexture).

* Add more getters to LightingShader

* The internal shader is a normal ofShader again (not a pointer)

* getShaderName() becomes a pure virtual function of ofxShadersFX::Shader,
  and thus must be implemented by any shader (not just Lighting ones)
Modify all GLSL330 shaders to incorporate textures.

A texture can now be applied and shaded at the same time.
v0.3: All GLSL330 Phong & Blinn-Phong shaders now work.

Merge branch 'develop'