Keybinding to take a debug snapshot while the switcher interface is up

[numist]

A lot of the issues I've been experiencing lately have happened when the interface is being presented, which makes it difficult to take a timely debug snapshot. Switch already responds to , when the interface is visible to show the preferences window, so this path is fairly well-trodden already.

Also, the debug snapshot should include the main state machine's state at the time of the snapshot.