[Delivers #49067191] Allow creation of Digital Object from instance linker

Allow creation of a digital objects from a linker.
Allow browse/create from linkers rendered in a modal.
And patch twitter bootstrap modal js to not break (recursion error) when multiple modals are displayed.

So now a user can open a Create New Digital Object form, add a subject subrecord form, open browse or create a subject from that linker... linkers from within linkers...