Enable SIGINT (Ctrl-C) to kill testall instead of leaving it running.

It's quite convoluted, but basically it is a cascade of traps leading
up to killing the actual testall process. Note that it does not kill
any jobs that testall might have created. The hope is that these will
quit on their own in a short time. Basically each level you you want
to kill requires a trap in the parent.
On Fri, Jul 11, 2014 at 3:32 PM, Kristian Amlie <notifications@github.com>
wrote:

> In tests/acceptance/tool_wrappers/elevate.sh:
>
>   # Elevate does not preserve return code, so use the return code we stored above.
>
> Right, good point. It is a testament to my state of mind after looking at
> this for too long...
>
By the time a developer is done with re-arranging the code, the
comments embedded in it have typically become invisible to
that developer !

Notice that your commit message still refers to "you you",

    Eddy.