Bug 7731 [Follow-up] Library should be used instead of branch and site

Bug 7731 [Follow-up] Library should be used instead of branch and site

This patch corrects new and old instances of the use of the
term "branch" and replaces them with "library."

Signed-off-by: Melia Meggs <melia@test.bywatersolutions.com>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
All tests pass, changes look good.
Also inlcudes some bookseller > vendor changes.
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>