[rake] add SUDO and PROPS parameter to the oar:generate task, so that generated lines include optionnaly a sudo prefix, and that a oarnodesetting can be limited to a given parameter.

[grenoble,lille,luxembourg,lyon,nancy,reims,rennes,sophia] Rework the [monitoring][wattmeter] entry for all nodes so that it is derived from the data in [sensors][power][via][pdu] or [sensors][power][via][ipmi]

[rennes] advertise in the reference API that parapide nodes have a 'power' metric entry (shared) in the Monitoring API

[nancy,grenoble,reims] move description of pdus to short uids instead of fqdns to be coherent with entries described in the pdus section of site description. Update reference metric from pdu to power to reference the metric hosted by kwapi

[grenoble] Rename measure to port for pdu description, cleanup spurious pdus in site description, referenced properly the block measure available for clarity