Downloadable acls on Cisco

Adds the downloadable acls feature on the cisco catalyst 2960.
Also adds it in the admin interface (that could be reworked)

This can then be used to push the web auth acls using packetfence instead of configuring them in the equipment.

For review and then merge if the admin interface is ok.
Cisco Catalyst 2960 2970 3550 3560 3750 4500 6500