Notification of changed shared docs

Notification of changed shared docs

If I create a doc, then share it with three other users userX, userY and userZ, then I would like the other users with whom I have shared the doc to be able to easily notify me that they have read and (possibly) edited the doc.

Scenario:

1. I create a doc testDoc1
2. I save the doc and share it with userX, userY, userZ
3. userX, userY and userZ receive email informing them of the shared document.
4. UserX opens the doc and makes some edits and saves it.
5. userX clicks a button "Notify Users" which:
a. brings up a dialog with the IDs of other document users already populated
b. userX can now choose to UNcheck some users
c. Optional: userX can also type a message
6. Click "Submit" and all the other users of the document (i.e. me, userY and userZ) receive a notification that userX has edited the doc.