plugins do not comply with quantum_plugin_interface

From quantum_plugin_base.QuantumPluginBase.get_network_details:

        :returns: a sequence of mappings with the following signature:
                    {'net-id': uuid that uniquely identifies the
                                particular quantum network
                     'net-name': a human-readable name associated
                                 with network referenced by net-id
                     'net-ifaces': ['vif1_on_network_uuid',
                                    'vif2_on_network_uuid',...,'vifn_uuid']
                    }

Plugins return a 'net-ports' attribute instead of net-ifaces.
The net-ports sequence describes id, state, and attachment for each port, where as the net-ifaces attribute requires a list of interface identifiers.
Quite interestingly, all the plugins behave in the same way.

Possible fixes:
1) Change the plugins to fulfill the spec of QuantumPluginBase
2) Change QuantumPluginBase and accept the current implementation in the plugins as "de facto" standard.

Fixing this bug is a prerequisite for Bug #834012. Targeting diablo-RBP for this reason.