This is sort of the reason for this ticket (and to keep us from having to maintain a fork), but we depend on some of the modifications and I don't know (for all of them) wether they are still used/needed or if they should just be dropped. (I added Yves to cc some time ago as he did most of those changes afaik)
Also premake-dev (which will become 5.0) changes a lot of the api so we will probably have to do some work once that is released (or hits beta).
And just that I mentioned it here #1516 should probably be fixed properly and submitted too..