Alter the release node form to set values for the version element fields as determined by the label_version_mapper plugin

I've got some time on a train today, so I'll try to get this (and #2145667: project_release_node_presave() should only parse the version string if the version elements are not already set) working.

This turned into a bit of a mess. :/ Since the form elements for the version subfields are generally configured to use the 'hidden' widget, I couldn't figure out how to set the values directly via altering the form. Instead, the current patch in #2145667: project_release_node_presave() should only parse the version string if the version elements are not already set uses an array for the flag where we tell project_release to preserve these subfields, and it walks over that array and directly sets the values during project_release_node_presave(). Not super clean, but working via local testing. If someone has a better idea, I'm happy to code it up, but since this is now working, I don't think it's wise to spend a bunch more time on this.

Whoops, realized I had uploaded the wrong version of the patch. The one from #2 wasn't correctly handling the case when you edit an existing release node. This one should work for that, too.

Via more testing on http://dww7-drupal.redesign.devdrupal.org I realized I had a few trivial typos that was preventing this from working as expected on a real d.o clone. New patch is working nicely for adding and editing both core and contrib releases, with and without 'extra'. I think this is ready to go, unless someone has a better idea on how to propagate these values to project_release directly via the field form elements.

Pushed http://drupalcode.org/project/versioncontrol_project.git/commit/943ea58 and deployed live.

Thanks!
-Derek