Supporting "--no-property" option will apply user a convenient
way to clean all properties of volume snapshot in a short command,
and this kind of behavior is the recommended way to devref.
The patch adds "--no-property" option in "volume snapshot set" command,
and update related test cases and devref document.

Change-Id: I5f10cc2b5814553699920c4343995b2e11416e4e
Implements: blueprint allow-overwrite-set-options

In network_qos_rule_type.py, network_service_provider.py, server.py and
volume_snapshot.py, the description format is using """ """.
In this patch, the former format is replaced with "_description = _( )".

Change-Id: I6863b01d3534e033df745070037ee45286745c92

Add "--bootable", "--non-bootable", "--read-only" and "--read-write" options
to "volume create" command for setting some attributes at the time of crration.

Change-Id: I71b4e9fccb4ee0ab1a90e7179d6d2d34dbbae909
Implements: bp cinder-command-support

Add "--name", "--status" and "--volume" options
to "volume snapshot list" command for filtering results.

Change-Id: I72db1abce7701f31598deec34801a4d1f5713870
Closes-Bug:#1645252

I think admin users will like to see the "Is Public" column
in volume type list since they can know the volume type
is public or private, so add "Is Public" column in volume
type list

Change-Id: I3f6e297a7adf82a275debbd87d2c4da415aa1360
Closes-Bug: #1643861

Leverage the new cliff command class attribute (_description)
to get the help of a command, this allows us to mark strings
for translation. We could not do this before since the help
was grabbed from the docstring.

This also depends on a new release of cliff and a bump to the
minimum level in osc's requirements.

Closes-Bug: 1636209
Depends-On: Id915f6aa7d95a0ff3dc6e2ceaac5decb3f3bf0da
Change-Id: I8673080bb5625e8e3c499feaefd42dfc7121e96f

Similar to what 'volume list --all-projects' does, 'volume backup
list --all-projects' list volume backups accross all projects.

Change-Id: Id5dda9b5adc822c4ddfb2dda339946d3322858e2