Repo conflict removal project (and other fixes)

Sorry for the long wait.

No worries, it's not like there's a deadline or something  Really appreciate your work!  

I probably won't have the time to work on this for the next few weeks, since I'm currently working on another modding project for another game. But once the bulk of the work is done for that one I'm gonna get back into Doom for sure.
I still have a few things on my list that needs fixing, for example the Flamer Rebel (from the Strife Rebels Pack) has a serious bug that gets him stuck in the firing state indefinitely, and the Medic Commando's heal attack can target monsters behind walls.
On the long term I'm also planning to finish some older submissions that were rejected before, if I can get permission from the original authors. Plus I still need to finish some of my own monsters that are pretty much done code-wise but are still lacking unique sprites.

Every weapon has been uploaded, some with minor modifications.