qtcurve (a native style engine for Qt and GTK)

This is a set of widget styles for Qt4 and GTK2 based application.  The
underlying work is based upon Blue/FreeCurve -  however, *extensive*
modifications have been made.

This slackbuild only build the QT4 and GTK2 engines with QT5
explicitly disabled as this version fails to build with the QT5
version available on SBo or the package from Alien.

It replaces both the QtCurve-KD4 and QtCurve-GTK2 as they have been
merged into one single source.