Added doc support for Floating API extension

This adds doc support for action "removeFloatingIp".
(Support for "addFloatingIp" was added on a previous change, but corrected the URI this time)
New sample files:   src/wadls/compute-api/src/api_samples/os-floating-ips/floating-ips-remove-req.json
                    src/wadls/compute-api/src/api_samples/os-floating-ips/floating-ips-remove-req.xml
Modified: src/wadls/compute-api/src/ext/os-floating-ips.wadl
Needed to add a new resource id, since modifying the existing one would affect other two methods.
This matches now: https://answers.launchpad.net/nova/+question/210126
Fixes: bug 1073763

Change-Id: I7515b94800924731f5c103611e56e4ef6f127c6f