Added RadosGW support

Originally https://github.com/crowbar/barclamp-ceph/pull/55

Partially ported from upstream cookbook.
But it does not mean apache can owns what it should not, see

    d52-54-00-71-64-93:/var/run/ceph # l /var/run/ceph/
    drwxr-xr-x  2 wwwrun www  4096 18. čec 09.27 ./
    drwxr-xr-x 22 root   root 4096 18. čec 09.28 ../
    srwxr-xr-x  1 wwwrun www     0 18. čec 09.27 ceph-client.radosgw.d52-54-00-71-64-93.asok=
    srwxr-xr-x  1 root   root    0 18. čec 09.27 ceph-mon.d52-54-00-71-64-93.asok=
    -rw-r--r--  1 wwwrun www     5 18. čec 09.27 client.radosgw.d52-54-00-71-64-93.pid
    -rw-r--r--  1 root   root    5 18. čec 09.27 mon.d52-54-00-71-64-93.pid
    srwxrwxrwx  1 wwwrun www     0 18. čec 09.27 radosgw.d52-54-00-71-64-93=

Also, see this note in documentation http://ceph.com/docs/master/radosgw/config/#adjust-path-ownership-permissions about the possible need to change ownership