Retry merge folder rename if it doesn't work for the first time after one second.
Make it possible to become op on a headless server.

The config file contains now a one time authorization key which can be used
to get op rights on a headdless server.
Merge PR #1427 by @flo - fixes #1403 (save game crash)
Merge PR #1429 by @IWhoI - depth of field
Add CommandParameter annotation on a new command
Merge remote-tracking branch 'upstream/develop' into develop