Feature request: prohibit actions outside the bounding box

[Andre68]

I would like to see an enhancement to prohibit all actions outside of the bounding box(es).
If the user tries to change something JOSM should give a warning message. The user could be enforced to download the area first.
There could be an option to deactivate this enhancement.

Possible complicacy: Not only manual actions should be prohibited then. Also actions of plug-ins like "simplify way" should take this into account.

This would for instance prevent breakage of connections to other ways.

[anonymous]

Duplicate: #230.