Move d2x-rebirth/libmve/decoder16.c -> d2x-rebirth/libmve/decoder16.cpp
Move d2x-rebirth/libmve/decoder8.c -> d2x-rebirth/libmve/decoder8.cpp
Move d2x-rebirth/libmve/mve_audio.c -> d2x-rebirth/libmve/mve_audio.cpp
Move d2x-rebirth/libmve/mvelib.c -> d2x-rebirth/libmve/mvelib.cpp