RFC: color diagnostics markers

[Jakub Jelinek]

On Tue, Apr 02, 2013 at 04:26:37AM -0500, Gabriel Dos Reis wrote:
> > IMO we also want that autodetection and default to auto.
> 
> I disagree.
> For this release, I think the default should be off.  We need more

I think a year is plenty of time to agree on the default color scheme
(and yes, the default certainly has to be usable/readable both on black-on-white
and white-on-black terminals), but at least having an auto/never/always
option allows one to choose, we can discuss what will be the default
later on.  The default could very well also be never if GCC_COLORS isn't
in environment and auto if it is, or similar.

	Jakub