It now also supports Windows 8 detection.
Function have been renamed from buildSystem to operatingSystem
as it does not really returns build system anymore.
QTWEBKIT_FROM_2_2 - >= 2.2.0
QTWEBKIT_TO_2_2 - < 2.2.0
QTWEBKIT_FROM_2_3 - >= 2.3.0
QTWEBKIT_TO_2_3 - < 2.2.0
It also check whether Qt5 is used and if so, it will
compile all features just like the QtWebKit version
was 2.3.0