Various work in preparation for university assignment.

Updated CMakeLists.txt to acommodate new include directories.
Updated submodule DTex to newest commit.
Updated submdoule DMath to newest commit.
Moved plenty of headers that should be global into the include directory.
Added mouse functionality to Application system, was removed when switched from SDL2 to GLFW3.
Removed some responsibilities of AssetManager now that DTex is used as primary texture loader for the project.
Moved all Transform functionality into SceneObject class.
Added SceneObject::GetRightVector(), GetForwardVector(), GetUpVector()
Updated .cpp files to use new include folder for headers.

Signed-off-by: Nils Petter Skålerud <np_skalerud@hotmail.com>