add option to send prefix hint for requesting desired prefix length for delegation

This change adds an option on the interfaces page for sending a prefix hint for the selected delegation size. If enabled, a "prefix" field requesting :: with the appropriate prefix length (64 - dhcp6-ia-pd-len) is added to the "id-assoc pd" entry in the dhcp6c config file. This hint is required for requesting prefixes shorter than /64 from Comcast.
Make sure to account for IP aliases on lo0 here, or they get duplicated on each CARP sync
s/BSDP/ESF/
Fix indent and whitespaces
Add actions (block or pass) to Captive Portal passtrumac
Add action to auto created passtru mac rule
Change 'Pass-through MAC' tab name to reflect current reality
Use same tab name on all pages
Make captiveportal_passthrumac_delete_entry() return rules instead of execute them as other similar functions do
Remove unused variable $macdb
Add action to auto created passtru mac rule
When block a MAC address, add it to a DB to make it possible to redirect it to a URL
Delete the old mac when action changes, not the current one
Make sure db doesn't exist when start to configure macs
Add a redirect url option to blocked macs
Redirect blocked macs to desired URL or show an error message
Do not add a ipfw rule to block mac since auth can take care of block or redirect it
Remove call-time pass by reference for do_input_validation, helps ticket #2565
Remove call-time pass by reference from traffic shaper files, it should fix #2565
Fix php short tag opening and silent php -l