Changed the movement way to be more Cube World-like
Reversed the camera movement to be more Cube World-like
Made a texture class, added a defaultTexture for meshes and adapted the
core to it, also removed useless imports
Created a mesh package and moved mesh and box to it
Moved program class to shader package
Moved Vertex and TexturedVertex class to mesh package
Set Escape key to grab cursor and so added constant mouse following