bug#12911: 24.3.50; let users decide where (& perhaps whether) `emacs_backtrace.txt' files are written

[Stefan Monnier]

>> There's no reason for Emacs to change its behavior
>> on GNUish hosts.  People on these hosts are used to
>> the current behavior with stderr.  Any problems
>> in this area are limited to Microsoft platforms, and
>> can be solved in a Microsoft-specific way.
> There are no problems on Windows, either.

There's clearly a problem: creating a file emacs_backtrace.txt in some
"in your face" directory annoys some users (and I'm sure we can come up
with funny hypothetical scenarios where it leads to serious breakage of
god knows what).
Hence the suggestion to use ~/.emacs.d which is much less "in your face"
and much safer.


        Stefan "Boy do I wish we never moved away from plain macros"