* Fix the missing os in command in example
* change os in command example to openstack(3)
* change os in command example to openstack(2)
* change os in command example to openstack
* Add support for clearing router gateway
* Add doc for Searchlight client
* Tivial:update the description format in volume_snapshot.py
* Add filtering options to the address scope list command
* Add support for setting router gateway
* Add --default option to "volume type list"