[IMP] Let collaboration managers access material
[IMP] Let collaboration managers access material

 - fixes #745
 - also override file protection and allow global vc managers

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