Backport r13424 and r13580 from trunk: RefWorks export support

Backport r13424 and r13580 from trunk: RefWorks export support

Patch from Warren Layton implementing RefWorks export via SuperCat:

"The patch a new transform, MARC21slim2MARCtxt.xsl, which converts MARC
into the MARC-ish plain text format accepted by RefWorks (see [1]).
The patch also adds a new feed to SuperCat, called "marctxt"."

As well as a reworked patch for the default opac skin to expose this
functionality as a link next to the "Place a Hold" link.

git-svn-id: svn://svn.open-ils.org/ILS/branches/rel_1_6_0@13582 dcc99617-32d9-48b4-a31d-7c20da2025e4