Raising the Emacs frame when ed/debugger/inspector pop up

[Luís Oliveira]

Hello,

When developing GUI applications, I find it essential to have the Emacs
frame pop up when my application signals an unhandled error. The problem
is that the debugger will often pop up while I'm interacting with the
application (and Emacs is usually hidden somewhere beneath it), so I
would often be left staring at a frozen GUI not understanding what was
happening.

This pull request <https://github.com/slime/slime/pull/92> makes the
frame raise.

It also does the same thing when entering `slime-ed' and
`slime-open-inspector' for similar reasons. In my particular case,
sometimes those events come from the application GUI, sometimes from the
Allegro CL IDE.

I have two questions for my fellow SLIME users:

  1. is there any situation where this behaviour would be undesirable?

  2. if so, we need a customisation variable. Which behaviour should be
     the default one?

Thanks,
Luís