pfSense

Do not allow to add a vlan tag on the same interface when it is used by qinq.

Add description even for parent QinQ vlan.

Allow QinQ interfaces to be assigned.

• Hide interfaces internals to other code and use the propper interfaces.
  Basically use get_interface*() functions instead of accessing fields like 'ipaddr'/'descr' etc...
• Make get_interfaces_with_gateway less heavyweight by getting information from the configuration stored in config.xml...

Clarify that ranges can be specified and add a fix to not leave the upper limit of the range unused as a tag.

Fix copyrights.

Add GUI pages for QinQ missed in previous commit.

Bring in support for QinQ. At this time it is limited to only 2 levels.

Don't check for overrides, that's a valid config.

Take care of cleaning the ip alias when we delete an entry of ipalias type or modify it.