[Feature Request] Customisable popup menu & short-cuts

Perhaps in Preferences:Control dialogue, add an option for editing popup menu; and another option for editing short-cuts (ideally also allowing mouse left-click and middle-click to be set).

The program is good, it's just unproductive to have to learn & remember different short-cuts for ten different graphics apps (viewers, editors, etc.). Customising would allow users the option of maintaining consistent controls they are comfortable with.