added custom collection page view with video scroller and pdf reader [ci-skip]
set cc_article uploader to only accept pdf for now
Modifies Openvault::Pbocre.get_model_for to find existing model matching pbcore identifiers if exists in Fedora, otherwise, returns appropriate model that pbcore xml describes.
Attempts to make variable usage and inline docs a little clearer.
added spec for cc_related_link [ci-skip]
removed mp4 from commit