[FIX] bunch of broken stuff over http requests in new routing thing

* make ModelConverter use its regex for data extraction so
  replacements can just fixup the request and don't have to mess with
  _uid

* replace routing_map property by method, for unknown reasons the
  property does not work at least overridden (it's not found) and I
  don't care enough to wonder why

* arguments result from MapAdapter.match() is a mapping, not a
  sequence. Iterate through values()/itervalues() otherwise we'll
  never get a browse_record to do the uid substitution on, only
  strings (params names)

* inject arguments from URL map/match into the function before
  executing it, this was apparently lost during the transition

* reintroduce get_db_router for third-party code needing to generate
  URLs