Dashboard reconstruction  performance reporting

This implements the performance curves reporting to the DashBoard performance monitoring service : 

http://dashboard43.cern.ch/dashboard/request.py/luminosityhome

According to the ticket specifications, is only valid for ReReco and PromptReco. Is tested in the Tier-0 agent and it goes fine, would be interesting to have it tested in a ReReco agent.

Can't be merged before #4434, depends on code which is there.