[#33838] Generate version of atom feed from JVersion

http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=33838&start=0

## Testing Instructions
Check an atom feed of a component. Before patch the < generator > tag will show the version as 1.6. After patch it will show 3.3 (and pulls the version number from JVersion so will not need updating in the future)
ah oh right, my htmlspecialchars suggestion was at wrong place!
it's JVersion that needs wrapped.