Suggestion / Compute extent from keyword / Fix failure when keyword contains accent.

This does not happens on GeoNetwork develop (see https://github.com/geonetwork/core-geonetwork/commit/ff74e87583982fcdaace750e14a5e55230b7cdc3).
Only applies to geOrchestra (on both jetty and tomcat).
BTW, the fix using a Java function instead of a XSL document call is probably faster. Could be applied to GeoNetwork but it could be nice to fix the TODO.
Merge remote-tracking branch 'origin/georchestra-13.09' into georchestra-13.09

Conflicts:
	web/src/main/webapp/WEB-INF/data/config/schema_plugins/iso19139/process/add-extent-from-geokeywords.xsl