[IMP] new routing thing

* fix nameerror on SessionExpired exception not being imported
* remove pointless RequestUID instantiation by single placeholder object
  - may be replaceable with a LocalProxy or something along those lines?
* rename default/nodb routing map
* make better use of werkzeug API
* move lazy routing_map instantiation to property in ir_http.find_handler
  - do we have some sort of lazy_property?
Merge branch 'master' of bzr::lp:openobject-server