Knm refactoring

[Will Stephenson]

I've finished (committed) most of the Knm:: refactoring that was left 
after the weekend's sprint.  I was having an awful time forcing 
Knm::Externals and KnmInternals onto the existing codebase so I took the 
decision just to merge them as Knm::.

The broad plan is to have a much simpler applet that is easy for non-NM-
specialists to hack and move the logic into the KDED module (where it is 
insulated from crashes in or crashing Plasma).  Crashing KDED is also 
pretty bad but I think this is the safer home for it.

We will allow the applet to control different network management backends 
(NetworkManager, wicd, ConnMan, ...) using different implementations of 
the KDED module that present a standard dbus interface to the applet. 

The configuration UI, KCM and storage format are shared - we hope that 
the NM-derived config schema is comprehensive enough to cover other 
systems, and it is independent of NM so we can extend it if needed.

The next steps are to complete the shared library for the KDED module and 
adapt the applet to use the new KDED module. 

Dario, could you let me know when you have committed the pure KDED module 
class and I'll review it and use it in the NM backend.  

I am going to start on the applet now.

Will