[tlbuild] Patching pdftex

[Florian Breitwieser]

> The initial search paths are determined from the texmf.cnf file
> found in source/texk/kpathsea/texmf.cnf This file is converted
> to a header file and included in the binary where to search
> for the realy texmf.cnf file.

Thank you again for the explanations. I will check the paths when I
want to have a local installation. But for now I am very happy having
pdftex-patched (or rather, in fact, pdftex-newest w/o patches as it
was fixed already by Peter Breitenlohner) in /usr/bin.

Best,
Florian