Contact search widget used in Activity, Case and Email forms should use the same back-end PHP class as quick search and contact auto-complete

Currently the contact find/select widget (facebook token widget) used in Activity, Case and Email forms uses a separate php class and does not respect the search configuration options available for quick search / contact auto-complete widget.

The facebook token widget supports selection of > 1 contact and this feature is needed for these forms. However, the Ajax.php class used by quick search needs to be modified to return a data format that is compatible with this widget.