Set multi valued option manually in ceilometer config

openstack-config uses crudini which doesn't support multi valued
option in current version 0.3, duplicate set will overwrite previous
value instead of creating a new one, so we need to do it manually.

Note, this patch also adds a warning for openstack-config.

Change-Id: I1165c229ad4380de3f5dbc2a8e994e12f446f81f
Closes-Bug: #1269480
backport: havana
Update nova option listings with latest autohelp code

Duplicate options disappear. Options begin to appear in the
right place. Default values are sanitized. Newlines are at
the end of files.

Change-Id: I1e8df9f65483e0d44aff22cb4a99830116ebf095
Merge "Set multi valued option manually in ceilometer config"
Merge "Update nova option listings with latest autohelp code"