Initial commit of texture support
Adding a texture manager to manage adding and removing textures. Avoids re-loading identical textures.
Adding a default texture to the manager.
Falls back to default texture.
Merge branch 'master' into texture-support
Now parses mtl files and new materials.
Splitting up faces in model into a list of faces by material.
- Added texture slots IDs to TextureManager
- Binds to current shader program now before any texture GL calls
- Added "removeLight" method to Model
- Added getter for default texture
- Added sampler to the fragment shader
Merge branch 'master' into texture-support

Conflicts:
	src/shaders/fragment.frag
- Began writing shaders to support texturing. 
- Changed ATAT obj and mtl file to all use the default texture.
- Added appropriate methods to return texture slots (currently only one
sampler anyways)
- Added uniform locations for texture shader variables
- Added checks to Parser (to avoid NullPointerExceptions if materials
not found)
- Early (and buggy version) of texturing implemented
- Fixed bug with segmentation fault in shader (slot Id and index are for
some reason offset by a constant)
- Draws are now per material (instead of per model) - in the future each
material can support (under the current scheme) textures for mapKd,
mapKs, and mapKa. 
- A call to glUniform has to be made during model setup (for texture
sampler) which is very awkward because I had to call glUseProgram there
assuming the shaders were already set up
- Fixed bug with glTexImage2D call - we are giving it GL_RGB data, not
GL_RGBA
- Fixed bug with Kd not being passed through to the fragment shader
- Obj + Mtl support broke non-Mtl obj files (this needs to be fixed for
primitives)
- A lot of the code is very disorganized especially for texturing
(prototyped a lot of stuff)
- Removed deprecated member variables from Light class
- Added sphere obj/mtl/textures to repository
- Fixed RGBA support
- Cleanup up Model class and vertex shader
- Added support for multiple textures in a model
- Cleaning up code
- Updated ATAT model for testing
Merge pull request #6 from jtmzheng/texture-support

Texture support added to master