Radosgw port from upstream (WIP)

1. This is not tested yet.

2. New comments (like 'this is from file XY") are for review only, will be removed


Depends on https://github.com/crowbar/barclamp-ceph/pull/56
Maybe I have something wrong, but with this setting, the socket path is not accessible to the user which is supposed to run the service ('www' in the init script). 
Shouldn't we create /var/run/ceph/radosgw subdirectory that would be owned by this user? @mjura?