Disable "Users/Members" for Non-Admin #2433

Hey there,
I'am using an german Piwik so may "Users" or "Members" is not called so.
I mean the Preferences, which user have acces to wich Website-Report.

For an new Project of mine, I need to show this dialog just to the Piwik-Admin, not to the Piwik-Users.

For Piwik 1.4 I implement it on my own, but can you add an Setting to the Piwik-Admin in the next Piwik-Update?
I think this is an small, but needfull Enhancement, the implementation-time should be short (but I don't know the Sources^^)

This is planned for #1568. No ETA on when it will be implemented though.