Add RHManageEventBase
Add RHManageEventBase

and use it in some event management RHs

DirkHoffmann/indico,OmeGak/indico,ThiefMaster/indico,pferreir/indico,mic4ael/indico,indico/indico,mvidalgarcia/indico,DirkHoffmann/indico,ThiefMaster/indico,ThiefMaster/indico,mic4ael/indico,pferreir/indico,indico/indico,mvidalgarcia/indico,OmeGak/indico,mvidalgarcia/indico,pferreir/indico,mic4ael/indico,OmeGak/indico,indico/indico,DirkHoffmann/indico,DirkHoffmann/indico,ThiefMaster/indico,mic4ael/indico,pferreir/indico,mvidalgarcia/indico,indico/indico,OmeGak/indico