python-pyqt: new package

python-pyqt: new package

[Thomas:
 - Remove dependency on python (already a dependency of python-sip),
   and add a dependency on host-python-sip, since python-sip no longer
   depends on host-python-sip.
 - Make the code Python 2 / Python 3 compatible (both have been
   tested).
 - Fix indentation all over the place.
 - Remove double quotes when defining variable values, not needed.
 - Add <pkg>_BUILD_CMDS to do the build process separately from the
   installation.
 - Create a PYTHON_PYQT_CONF_OPTS variable with all the config
   options, since some of them are now conditional.
 - Use 'compileall' to byte-compile the dummy __init__.py.]

Signed-off-by: Gwenhael Goavec-Merou <gwenhael.goavec-merou@trabucayre.com>
Cc: Sergey Kostanbaev <sergey.kostanbaev@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>