This was done to clean up the license and to ensure that any commercial fork of the engine has to obey the far stricter requirements concerning source distribution. The old license was compatible with GPLv2 whereas combining GPLv2 and LGPLv3 force a license upgrade to GPLv3. The license of code that originates from ZDoomGL has not been changed.
# Conflicts:
# src/CMakeLists.txt
# src/p_setup.cpp
# src/r_defs.h
# src/version.h
This only updates to a compileable state. The new portals are not yet functional in the hardware renderer because they require some refactoring in the data management first.
After thinking about it for a day or so I believe it's the best option to remove all compatibility code because it's a major obstacle for a transition to a core profile.
