Support for secure mesh in userspace and other mesh fixes

These patches add the capability of implementing the Authenticated Mesh Peering
Exchange entirely in userspace.  Open mesh networks can still be created
without the need of a userspace daemon.  For secured mesh networks, the daemon
takes control of the lifetime and the peer link state of mesh peers.

While working on this we encountered a few issues with the mesh stack which are
that are fixed in separate patches also included in this series.  

For a working userspace authentication daemon you can look at the ampe branch here: 
https://github.com/cozybit/authsae/tree/ampe

Cheers,

Javier