Add LINC-Switch to Mininet

LINC-Switch is an OpenFlow software switch written in Erlang. Currently
the latest supported version of OpenFlow is 1.3. More information can be
found here: https://github.com/FlowForwarding/LINC-Switch. Tutorial
explaining how to run LINC-Switch on Mininet can be found here:
https://github.com/FlowForwarding/LINC-Switch/blob/master/docs/mininet_integration.md.
FlowForwarding also provides easy to setup virtual environment
that is equipped with all required software to run Mininet with LINC:
https://github.com/FlowForwarding/LINC-Environment.