Merge pull request #4942 from RosettaCommons/roccomoretti/header_fixups
Some header/namespace fixups.
There's some forward headers we didn't have that we probably should have. (Most notably, core/chemical/rings/RingConfomer.fwd.hh which was called out specifically by the code in places.)
Also, there was some "AUTO USING NS" stuff that is mostly pointless at this point -- we should either include the header or delete the using that was requiring it.
I also deleted a editor temporary file.