RFC: Moving C to its own directory

[Nathanael Nerode]

Richard Kenner wrote:
>     The loop over language config files (in the various configuration files) 
>     would be slightly simpler and less error-prone if each language had a 
>     subdirectory under, say, lang, and nothing but languages had such 
>     subdirectories.
> 
> I don't see that lang/* is any simpler than */config-lang.in, or at least
> not enough simpler to make any real difference.

The point is that currently we look for po/config-lang.in, 
intl/config-lang.in, fixinc/config-lang.in, etc. (waste of time, and 
could theoretically give false positives), and then we have to add 
whatever the file is for C.