Comment 5 for bug 1619703

Code, live tests, release notes pushed. Includes XUL UI bits, too, as a separate non-required commit.

http://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/berick/lp1619703-transfer-lineitems

For handling parts, I opted to leave all existing parts on the source bib record, even if all copies linked to a given part will be migrated to a matching part on the new bib record. My thinking was the source bib record still has the same parts, even if no copies link to all of them. This may be naive. If parts should behave more like call numbers, where the last copy out turns out the lights (i.e. call number is deleted or moved to the new bib, depending on whether a call number with the same label already exists on the new bib), that can be arranged.