Link modification and removal, oh my!

Also, fixing a bug which would have been present when ingesting a manuscript
into a collection, with ingest steps: After making a selecting, going back and
selecting a different finding aid would not wipe out the old value correctly.
Select node when going back through ingest steps.
Remove dsm() calls, 'cause derp.
Fix the derp in the function name.
Merge pull request #22 from adam-vessey/7.x-UCLA-27

Link modification and removal, oh my!