In DQMFileSaver, do not set umask, even when testing.
In DQMStore, save files encoded with ProtocolBuffer by explicitly setting permissions to 0664.
In fastHadd, set file permissions to 0664 for files merged and encoded with ProtocolBuffer.
Merge pull request #4881 from diguida/fix_PB_file_permissions_v2

Fix file creations and permissions for DQM histograms encoded with ProtocolBuffer: second round