Extending floodlightTopologyExporter with link capacities

This commit extends floodlightTopologyExporter to parse
a "capability" attribute that can be added to the input json
topology.
Removing VLAN PCE from link evaluation phase
Adding a TODO message regarding device capability learning
Updating sdnPSS dependency to 36f2da67d058d5b37d8aad4561e7d112cc82a694