bug#13141: 24.3.50; Be able to customize the info included by default for `report-emacs-bug'

[Stefan Monnier]

> It isn't sent. There is a hook that strips it out, but it is easy to
> defeat it, which is why you sometimes see it.

I've just changed this text to be a display text-property, so you can
see it, but it's not really part of the buffer: copy&paste into another
application will not copy it and it doesn't need to be stripped
explicitly before sending.
IOW it now requires extra work to keep the text, instead of requiring
extra work to remove it.


        Stefan