Camera: Fix incorrect order of arguments.

See: http://badlogicgames.com/forum/viewtopic.php?f=15&t=8291

Note that Matrix4 uses rotate(axisX, axisY, axisZ, angle) and camera/vector3 uses rotate(angle, axisX, axisY, axisZ). I would opt to have consistent rotate method and since openGL uses angle first, it makes sense to follow that.