Adding SSL support for RadosGW (WIP)

- UI part is missing
- hacks to work behind HAProxy (like for nova_dashboard) are missing

I think in other barclamps, we have something like:
```
"radosgw": {
 "ssl" : {
   'enabled": false,
   "ssl_crt_file": "/etc/apache2/ssl.crt/ceph-radosgw.crt",
   "ssl_key_file": "/etc/apache2/ssl.key/ceph-radosgw.key"
  }
}
```

Would it make sense to adopt something similar?

Also, no ssl_ca_file attribute?