[tabs] fix pb with non-lazy tabs: style isn't properly set due to missing jquery.ui activation. Closes #2465657 also do a small cleanup on the way, and properly implements render_entity rather than cell_call, as one would expect regarding default PrimaryView code.

#!/bin/sh -e
if [ "$1" = "purge" ] ; then
        update-rc.d cubicweb remove >/dev/null
fi
 
#DEBHELPER#
 
exit 0