This is to improve compile times because the MSVC compiler tends to become slow with large lists of source files in a single project.
This new project is still our stripped down copy of libadl, not the original, because that project contains a large amount of baggage we do not need.
# Conflicts:
# src/CMakeLists.txt
# Conflicts:
# src/sound/mididevices/music_adlmidi_mididevice.cpp