Fix pyqt formula upgraded to 4.11.1

- the custom QMAKESPEC hacks for Mavericks seem to not be needed any longer

- creating the `pyconfig.py` file by running `python configure.py` in a
  different folder seems to work, but I am not sure if this is actually still
  needed, so for now I commented this out. I have sucessfully built and used
  PyQWT even without this generated `pyqtconfig.py`. It's use is deprecated
  anyway it seems. I don't know if not having it breaks other stuff, which is
  why I left the code in the formula for now, albeit commented out.