[merge] Control-backspace to drop into the debugger

[Martin Pool]

Martin Pool has voted +1.
Status is now: Conditionally approved
Comment:
Fix self-vote (Aaron)

For details, see: 
http://bundlebuggy.aaronbentley.com/request/%3Ce01316480704162359m6128bc83vc823d9ca73d7ca8f%40mail.gmail.com%3E