Updated assimp and fixed last orientation issues

ext/assimp

res/dpr/utility/indirect_capture.vert

res/dpr/utility/math_library.glsl

res/dpr/utility/shadow.vert

src/headset/emulated_headset.cpp

src/scene.cpp

src/scene.hpp

src/utility/command_parser.cpp

src/utility/command_parser.hpp

src/vr_application.cpp