Add 690 for headings to enable link bib to auths - IRB 9/8/13
FBD: Implimented stopwords for hit highlighting.

Initial implementation of stopwords for hit highlighting. Currently
the words 'and', 'or', 'And' and 'Or' are hardcoded stopwords.

Future work should be to impliment the stopwords list into a system
preference.
FBD: Followup to hit highlighting stopwords

This followup add the ability to control hit the stopwords used by
highlighting via a system preference.