Rudimentary support for BATMAN Adv mesh networks

Created by: SunilMohanAdapa

Most of the changes are about adding additional fields/types for configuration with network manager. The final patch is a small NetworkManager dispatcher script to configure interfaces as BATMAN adv interfaces.

To configure a batman-adv mesh network: first create a connection with a Wi-Fi device, mode as ad-hoc, with a known frequency and BSSID. The name of the connection should have contain BATMAN in it. It should also have IPv4 method as disabled. Second connection should be created for 'bat0' interface after the first one is successful. It can be with method 'shared' for sharing internet connection and answering DHCP requests or 'auto' for acquiring IP address from another node in the mesh network.