Rename directory, py-qwt to py-qwt-q4
(Rename directory, wip/py-qwt to wip/py-qwt-qt4)
Import PyQwt-5.2.0 as wip/py-qwt-qt4.

PyQwt is a set of Python bindings for the Qwt C++ class
library which extends the Qt framework with widgets for
scientific and engineering applications. It provides a widget
to plot 2-dimensional data and various widgets to display and
control bounded or unbounded floating point values.
- PKGNAME to ${PYPKGPREFIX}-qwt-qt4
- Add buildlink3.mk
- Clean up TODO
Thanks Niclas Rosenvik for valuable suggestions and changes.