Update docs and add configuration options to allow use of RESTBase.
We don't actually need any special configuration in the service; the
metabook will pass along the required RESTBase info. But for local
development you should probably force the use of the v1 Parsoid
API (at least until we update all docs to use the Parsoid v2 API).
Change the defaults so that we don't pass along bogus prefix and
parsoid api information by default.