Allow multiple volume delete from cli like Cinder

In cinder project, we can use cli like follow:
cinder delete xxx yyy zzz
But in nova, we can not use follow command:
nova volume-delete xxx yyy zzz

This patch will add a feature in nova to allow multiple volume
delete from cli like cinder.

Change-Id: I4dd182673e58406a57d30c572ec3116f9f4ce315
Closes-Bug: #1262061
Don't slugify() None names

If image has no name, human_id can't be built.
Also slugify raises ValueError if None argument passed.
It affects Docker images.

Closes-Bug: #1267429
Closes-Bug: #1267130
Change-Id: Ib975775b441917eef2a650049cee9991d10c50d7
Fix logic for "nova flavor-show 0#"

For perviously logic, if flavor id is
start with "0Number", int(name_or_id)
will convert it to "Number". If flavor
id "Number" exist in DB, it will show
up for query with "0Number".
This fix enter flavor search logic at
the beginning. Also add one more UT
for this function.

Change-Id: Ic48ff4275978404064c0c6fce6f98181660aa84a
Fixes: bug 1268456
Merge "Don't slugify() None names"
Merge "Allow multiple volume delete from cli like Cinder"
Merge "Fix logic for "nova flavor-show 0#""