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 URI_location="LOCAL://">
  <TargetType/>
  <Libraries Enable_Python_Library="true"/>
</BeremizRoot>