bug#66317: Project mode-line

[Juri Linkov]

>>>>>> Thanks, I've tried this patch on top of Emacs master and it seems to
>>>>>> work well.  One small suggestion is to consider giving the project name
>>>>>> in the mode line a dedicated face, so people/themes could customize its
>>>>>> appearance.  (By default, it could just inherit from `default`.)
>>>>> Thanks for suggestion, will do on the second round after pushing the
>>>>> initial version.
>>>> I'm not yet sure whether better to add a new face or a new variable like
>>>> grep-hit-face and xref-num-matches-face that refers to the existing face.
>>>> Then it would be possible to set such variable e.g. to the face 
>>>> `vc-state-base`
>>>> that inherits from `default`.
>>> Personally I think a variable pointing to a face name is a somewhat
>>> redundant indirection, since customizing the face to inherit from some
>>> other face is just as easy as customizing the variable to point to a
>>> different face.  But either way works, of course.
>> Probably adding a variable would be more suitable since currently
>> there are no faces defined in project.el at all.
>
> FWIW, I don't have a strong opinion.

Ok, added a face variable.