adds CCS's changes to repository.
Changes <file ID="PDF00001"> to <file ID="PDF_ISSUELEVEL"> throughout.

As per Michael Dewsnip's memo, the ID attribute of <file> elements
referencing the issue-level pdf for an issue MUST be PDF_ISSUELEVEL in
order for Veridian to find it.  This patch changes all METS in the tree
that still have PDF00001 as the value of that ID.
some exploratory changes to the bmtn_springs app.
some new files for the bmtn_springs app.
Merge branch 'pdf-mets-update'

Merging the METS records created by CCS in order to
correct the "enormous PDF" problem.
Merge branch 'master' of https://github.com/pulibrary/BlueMountain