Added texture mapping to walls

main.cpp: No changes, just turning stuff on/off

common.hpp: Removed image width/height (textures) because now the image size is the dile domensions

grid.hpp: Added code to create and draw the plane under the rooms

textures/*: New textures to map the rooms. The only one being used right now is the composite one
Added SOIL library and new 3D models

SOIL.h: Library’s header. Simple OpenGL Image library. Used to load the texture given a BMP image file

models/*: New 3D models with both normals and texture coordinates mapping (the theapot and teddy didn't have)
texture.hpp: Removed the previous strategy to load image data from a BMP file. Using SOIL library instead. Way easier, and only needs a line of code to do so
Failed to migrate 3D modeling

model.hpp: Major change on the way how we load models. Since the previous models didn’t have normal and texture mapping data, the results weren’t visually appealing. Tried to migrate it but failed. Right now the data is successfully loaded, but an annoying allocation error is happening while computing the faces and reorganizing the arrays. I may rollback to the previous simple version (project deadline) because it loaded (simple) models, but it loaded something. I’m committing it so I can come back and work on this later, probably when I get XCode running (command line is OK, but sometimes you really need a debugger and printf isn’t enough).