[metapost] troublesome verbatimtex limitation

[Matěj Týč]

Hello,
when I want to use the verbatimtex stuff, it doesn't make sense to put
it in an include file, I have to define it in the file where it is used
in order to make it working.
Although it is possible to have only one metapost file for includes, it
is more convenient to actually have more of them. Not only because it
tells you something just by looking at the files in the directory, but
it is also better when you use version control software.
Including TeX header makes sense when you want to have consistent
illustrations and the text.
Although I understand that 'verbatimtex' can't change its behaviour due
to compatibility reasons, IMO it makes sense to provide an alternative
solution that would not have this limitation.
Hope that I have expressed this in a way that it is understandable :-)
Regards,
Matej