Syntax file for M4/Autoconf

[Pavel Roskin]

Hello, Vlad!

> This time I'd like to contribute a syntax file for M4 macroprocessor
> with autoconf support.
> (m4.syntax attached)

This looks very annoying.  Too bright.  Please try using the same
conventions as in C files.  In particular, comments should be brown, and
that applies to dnl too.

Also a common rule is to highlight only recognized constructs.  There is
no need to make everything yellow.

> Pavel, I'm sorry, but I misspelled word 'highlighting' in ChangeLog
> entry for js.syntax.

Fixed.

> Also, what do you think of adding numbers highlighting to C and Java
> syntax files?

I think it's a good idea, but I'm not sure about brightgreen for the 
numbers.

> There are some more changes that I'd like to contribute to c.syntax such
> as - alphabetic sorting of keywords

Fine with me.

> - better preprocessor directives highlighting

Maybe be hard if you decide to support more than on C dialect (K&R, ANSI,
C99).  Not all of them allow spaces before "#".

> - removing unnessesary syntax rules (for example we don't need to
> highlight '==' if there's '=')

Maybe we need different colors for them.

> What do you think?

Go ahead.

-- 
Regards,
Pavel Roskin