[Feature Request] Warn Before Merge/Push if Remote Branch Changed

[borankurut]

Before merging or pushing a branch, Fork should check whether the remote branch has changed since the last fetch.

For example, before merging origin/branch:

git fetch origin branch

If the remote HEAD changed, show a warning:

origin/branch has changed since your last fetch.
Remote branch is 2 commits ahead.

[DanPristupov]

That would increase an instant merge (100 ms) to a second.