Extended mesh management API.

[Idorobots]

Currently, the only means of establishing a mesh is via mDNS which is finicky and works about half of the time. On the usual, some devices fail to connect to a part of the mesh, while some other devices only connect to another part of the mesh, resulting in a giant mesh mess (incidentally what this project should have been called).

The devices should maintain the mesh by themselves and share current composition with newly joining devices. mDNS should only be used for mesh discovery, as only one of the available methods of establishing a connection.