Nav shuffle, refactoring opentreewebapputils

Moved bibliographic references to a dedicated page. Modified nav menus
throughout to reflect this. Streamlined creation of view-dictionaries.
Added support for taxon-search on all webapp pages.
Share the opentreewebapputil module across webapps.
Merge pull request #248 from OpenTreeOfLife/contributing-studies-page

Improved References page, refactored support module