Duplicating a publishing target causes (almost) unrecoverable error

[maxslabyak]

If you want to add a publishing target under System/Publishing targets and you end up duplicating the target, you get an .NET error of "same key exists," where the only way to recover from it is to remove all instances of the module from the Core DB, rename the target, and reinstall.

Would be nice to put an event in to prevent duplicating publishing target with same name, or make the error handling a bit more graceful