Made several changes to allow compilation on windows (for now, CMake passes, compilation fails):
-Modified Ogre and Bullet CMakes to not enforce /MT on Windows/MSVC;
-Removed Ogre RenderSystemGL glew implementation;
-fixed redefined CreateWindow bug on engine/3D graphic manager;
-Removed install dependencies from Ogre cmake;
-Updated external Ogre Dependencies pack for windows, removing freetype and OIS and changing how it finds zlib.

Updated gitignore;