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.