pyPdf => PyPDF2 transition breakage

[Jeremy Lainé <jeremy.laine@m4x.org>]

Recently the pypdf2 source package, was uploaded to unstable, and
forcibly took over the python-pypdf binary package. The problem is that
pypdf2 does not provide a "pyPdf" module, but "PyPDF2" which broke all
the reverse dependencies. I would suggest:

- pypdf2 be changed to provide a python-pypdf2 and python3-pypdf2 module

- the last version of python-pypdf be re-uploaded

- encouraging python-pypdf's reverse dependencies be patched to allow
python-pypdf | python-pypdf2

Cheers,
Jeremy