"Revert" command

I would find it useful to have a single simple key sequence to "revert" all changes made to a score since opening it. I know that in theory this can be done with Contrl-Z, but you have to do that multiple times, and it seems that I never really get rid of the asterisk indicating changes have been made. The command should probably give a warning and ask for verification.

If there is already such a command, please post. Thanks/