[tex-eplain] Problems with math symbols in pdftex outlines

[Karl Berry]

    In latex one uses hyperref and its very complicated macros,
    workarounds and hacks. 

Indeed, we adapted many of hyperref's hacks for Texinfo.  In fact I
simply stole some of the hardest-core code (with Heiko's permission).
\HyPsdSubst and friends.

I still wonder what the real specs are for the outline window.  In
particular, what character set it uses.  If the character set is
controllable by the document, more could be done.  Maybe someday I'll
research it.