prevent stripped change sets from being pushed again. (BB-13961)

I just had to strip a change set from one of our repos. The warning says that if someone pushes from a repo which has the stripped change set, the stripped changes will reappear.

It would be really handy if bitbucket remembered which changesets had been stripped and prevented them from being sent to the repo again.

Perhaps with an error message which says: These change sets were stripped - remove them from your repo before doing the push.