Bug 9554: single quote in didyoumean

When using "url" or "uri" template toolkit filters, I noticed that double quotes are escaped (%22), but not single quotes.
This causes sometimes a problem when URL is written in JavaScript code, in a string delimited by single quotes.

This patch corrects by using double quotes for js strings.
Also, adds a test for "didyoumean" feature : when feature is not activated, do not add corresponding javascript.

Test plan :
- activate OpacHighlightedWords syspref
- activate "didyoumean" feature for OPAC
- perform a search begining with a  single quote (ie "'sport")
=> look for javascript errors (you may use firebug)

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>