Nuclei.Communication: Add security verification

[pvandervelde]

From @pvandervelde on December 3, 2013 20:51

At the moment communication endpoints accept connections from everybody who matches their specified communication topics (which are broadcast around the world), which means that there is currently no way to limit connections to only those that we want to allow.

We need a way to only allow communication from endpoints that are known to be friendly. Some suggestions for how to achieve that are here: http://paulstovell.com/blog/x509certificate2

Copied from original issue: thenucleus/Nuclei#4