[PyQt] Provide metadata for source installs

[André]

Hi,
can you provide some metadata file (like egg-info or dist-info) when 
installing pyqt from source?

Currently an installed pyqt package is not recognized as intalled by pip 
which makes it difficult to use it as a requirement in setup.py.

The wheel distribution provides the metadata but that brings all the Qt 
library with it which is not usefull if you want to use the packages 
form your Linux Distribution.