add_user_to_group.sh

[avoidik]

could you please upload this also?

[thinkernel]

Do you just need the script or do you want me to uncomment those two lines in the gerrit-init.nohup?
I have an untested version on my local disk for long time. I really have no time to do this.
Also, I think it's very easy to add users into the groups by using the web UI.

[avoidik]

if you don't mind I'll do PR #3

[thinkernel]

Any PR is welcome! Your works impressed me. I still need to check it carefully since we're using this image quit a lot.