Add support for "git rebase --onto"
Those of us that employ a rebase-centric development model sometimes need to drop into the command-line to run "git rebase" with the --onto option.
The common use case is a longer-lived feature branch that several developers contribute to, and which gets rebased fairly often (e.g. weekly). If one developer has local commits that had not been pushed prior to another developer doing the weekly rebase (& force push), it is hard to migrate those commits onto the newly rebased feature branch without dropping onto the command-line to run "git rebase" with the --onto option.
The existing patch file feature request could be one solution, but still a bit manual. It seems like there could be a very sexy GUI gesture for this where you select one or more commits and just drag-n-drop them to a destination branch.