Fix v3 server rebuild deserializer checking with wrong access_ip key

When rebuild server with xml format, the xml deserializer code
are checking with wrong key. So rebuilding with access_ips doesn't
make any effect. So correct the wrong key 'access_ipv4', 'access_ipv6'
to 'access_ip_v4', 'access_ip_v6'.

Change-Id: I8fccf3727f193bf9142dc814a76a32d5ab1a1b0a
Closes-bug: #1221646
Fix docstring for disk_cachemodes

The docstring for the disk_cachemodes option implied a syntax that is
incorrect for a ListOpt.  Change the example to match exactly what you
would put in the config file for it to work.

Change-Id: Ie999d2799dba6c47facdc771e1cf6081d28d6b85
Closes-Bug: #1106423
Merge "Fix docstring for disk_cachemodes"
Merge "Fix v3 server rebuild deserializer checking with wrong access_ip key"