[tableview] enhance RelationColRenderer. Closes #2093184
* subvid should only be explicitly specified, or default when main view (vid)
is known to support it (eg 'list' / 'csv')
* new is_rtype_view boolean flag to ease usage of view based on original
entity with a relation name and role, as the 'reledit' view for instance
cubicweb-web: embedded-javascript-library usr/share/cubicweb/cubes/shared/data/jquery.js