[Salt-cloud] Add function for checking libcloud versions.

Everything else should need 0.13.2, but rackconnect will need 0.14.0.
Add a function to make custom requirements for libcloud as you would
need them.
[Salt-cloud] use list_nodes_full for extra dict

Rackconnect and ManagedCloud require the extra dict in the node data.  I
have also added the default options for those because the values are
not set immediately.