Bug 13672 - OPAC locks up browser when browsing items from series link with NoveList...

Bug 13672 - OPAC locks up browser when browsing items from series link with NoveList and OpacHighlightedWords

It appears that an empty string is sneaking into the list of words
to highlight and that is causing the browser to freak out.

Test Plan:
1) Enable NoveList
2) Enable OpacHighlightedItems
3) Search a title with a series (i.e. The Hunger Games)
4) Click into the record
5) Click on the series to search it
6) Click on a title in the search results
7) If Firefox doesn't crash, it gives the unresponsive script message
8) Apply this patch
9) Repeat steps 3-6
10) Browser doesn't freak our

Signed-off-by: Jason Robb <jrobb@sekls.org>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
could not confirm the problem, but small change and
highlighting terms on result list and couldn't find any
regressions in highlighting.

Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>