New restful machinery for multi-rels

The RESTful multi-rel path functionality, which allows accessing the
grid of a multi-rel via '<row_key>/<id>/ra/<relname>' has been
refactored to use a restful resolution *internally* by the store. This
allows these paths to work regardless of how complex the relation is,
since it now goes through the DBIC machinery.

Note: this is still not yet link generated in multi-rel columns, it has
to be manually entered (but this is about to change)

Also improved internal dispatch util functions/methods further

Also disabled the deprecated automatic 'ModuleDispatcher' root module
override stuff (see in-code commits)