Keep an updated copy of hierarchy field in source lists

[Brian Cardiff]

Source lists should have a hierarchy field with the same values as in the master.

1. Each time a source list is added to a project SourceList#prepare creates additional fields on the RM collection. Create the hierarchy field there.

2. Create a way to update the hierarchy definition from the hierarchy in the master.

3. Create a way to check if a hierarchy is up to date with the master.

4. Each time user request source_list details, run (3) and (2) if appropriate to keep the hierarchy up to date.