Proof of concept holdings-in-SRU results

Proof of concept holdings-in-SRU results

Based on what seems to be the best holdings option of a poor lot from
http://vdxipedia.oclc.org/index.php/Holdings_Parsing - apparently
standard MFHD doesn't exist, despite http://www.loc.gov/marc/holdings/hd852.html

As miker says, code from this should be factored out
from a few different places, and this needs to be much
more configurable, and holdings values need to be escaped...

git-svn-id: svn://svn.open-ils.org/ILS/trunk@13029 dcc99617-32d9-48b4-a31d-7c20da2025e4