Test different means of creating load balancers.

Including the API-specified minimal way: name and protocol.
Yard docs and optional parameters for lbs.
The "nodes" element is actually nullable.
Whitespace touchups.
Reorganize clb fixtures, add a minimal case.
Port and nodes are *not* required for LB creation.
Formatting stick!
Merge pull request #3110 from smashwilson/load-balancer-params

[rackspace] More optional parameters for Cloud Load Balancers