bug#1153: default for comment-style not very good

[Stefan Monnier]

> `comment-style' defaults to indent-or-triple.  

> This makes a difference only for modes that use a single character
> comment syntax, comment-region will use three characters to comment.
> For modes like assembly, shell, perl, etc this is very unusual way of
> commenting.  Even for elisp, triple ; is not the most used way of
> commenting.  Hence this version should not be the default, a more
> appropriate default would be 'indent.

Agreed.


        Stefan