merging duplicate works

[Jason Stirnaman]

I've pushed a feature branch of my own that enables an Admin to merge duplicates into a "master" version of a work. Instead of having to compare them manually and then just deleting the duplicate, it checks for duplicates (either accepted or unaccepted) of a work, does a simple calculation to determine the richest one, and then does a second check for equality before merging them, along with any unique attributes and associations, into the master.

It's not incredibly sophisticated and there are likely many cases unaccounted for so any feedback is appreciated.

https://github.com/BibApp/BibApp/issues/90#issuecomment-5639304

Jason