FIRST OF ALL, NOTE THAT FOR NOW THIS IS A NON FUCTIONAL VERSION OF THE RSTP
PROTOCOL; THERE'S STILL MUCH WORK TO DO.


- Check backwards compatibility with STP

- Code for BPDU processing.

- Code for sending BPDUs.

- Code for the State Machines.

- Create a "rstp_mng.[ch]" module based on IPC for the management of the daemon.

- Create a function to poll the link status periodically. A better aproach would
  be to receive some kind of notification.

- Create the functions that associate the RSTP port roles to the port states at
  HW.

- Before running, test that we don't have another instance of the daemon.

- For now we reserve static memory for the rstp parameters of the whole set of
  ports implemented at HW, whether they are dummy or not. To save memory we
  could only have the non-dummy ports and create a dynamic procedure to include
  and delete ports, as they change from dummy to non-dummy and viceversa. This
  would be useful if we envisage hot-plugs. (Here note the difference between
  dummy ports and the 'down' link status of a port; dummy ports are implemented
  in the FPGA but have no board attached).
