Merge pull request #1968 from RosettaCommons/roccomoretti/parse_xsd_desc_fix
Fix documentation on some of the common XSD parsing utilities.
There was a bunch of XRW TODO for documentation in protocols/rosetta_scripts/util.cc -- I changed this to something passable, as well as extending the utility functions to take (optional) descriptions, so you can have "TaskOperations for the low-resolution stage" instead of just a plain "TaskOperations to use" description.