[metapost] generic TeX interface?

[Taco Hoekwater]

Stephan Hennig wrote:
> 
> Dan, thanks for your clear and detailed comments.  I would like to
> invite others to comment to or add features to this list.  And Taco to
> strike out items that have only little chance becoming implemented.
> (I'm just not sure if I really want to _invite_ him to. :)

I am waiting on the sideline to see how this develops. I am in
fact quite eager to improve the btex.. etex subsytem because
integrating metapost into something like pdfTeX will be quite
problematic with the current makempx setup.

A few quick notes:

* page 64 in the manual explains some of the makempx mechanics
   (in addition to Karls remarks)
* The 4096 limit will go away when we switch to 64-bit calculus
   (planned for 1.1)
* current dvitomp handles dvips-style color specials already
* the label positioning stuff I have to look up

Best,
Taco