Merge pull request #5033 from RosettaCommons/roccomoretti/move_loop_relax
Move LoopRelaxMover to different library level.
PR #5028 has issues due to library levels.
This PR (being merged independently) should alleviate those issues by moving the LoopRelaxMover from protocols 5g to protocols 4. (into a new protocols/relax/loop directory). This also requires moving some utility functions from protocols/comparative_modeling/util.hh to protocols/loops/util.hh, but that's arguably the better place for them, anyway.