IDManager : refactored a bit, moved some code into PSKManagement.py. Now captures URI and PSK on new PYRO(S) and propose them when editing URI. Import/export still to be implemented.

<?xml version='1.0' encoding='utf-8'?>
<BeremizRoot xmlns:xsd="http://www.w3.org/2001/XMLSchema" URI_location="LOCAL://">
  <TargetType/>
</BeremizRoot>