Possibility to suscribe to reviews of other users

[boxdot]

• Relatively easy to implement.
• Hard: how to insure that the user won't subscribe to a review, which the user actually should not be able to see?

[gferon]

For the 2nd point, I think we can simply assume that you need to be a reviewer in Gerrit - that way it's visible to everyone.

[fbenkstein]

Additionally you should be subscribed automatically to changes you don’t own but where you uploaded a patchset.