Add ability to configure detailed DHCP/VLAN settings in InControl2

Currently, InControl2 allows creating VLANs with limited DHCP settings. However, the more detailed settings must be adjusted in the router’s interface directly. Moreover, a fix applied in a previous bug report (Ability to configure InControl2 VLAN settings (such as the DHCP)) seems to have disabled the synchronization of the basic DHCP settings between the router’s interface and InControl2, so that whenever a change is made in one it is not reflected in the other.

Ideally, all detailed VLAN/DHCP settings should be available in both interfaces – the router’s built-in management/configuration page, and InControl2. Otherwise, it just creates confusion and the unnecessary need to switch back and forth between both websites. (The reason I have to continue using InControl2 is because this is the only place where I can configure users for Captive Portals, otherwise I would do everything from the router’s interface which is more powerful and more user friendly).