Work around broken ATI X1600 drivers on Mac OS X
Work around broken ATI X1600 drivers on Mac OS X

The GLSL implementation messes up return values from functions so that
all our srcPixel()'s become black and several matrices are off. We
don't want to rewrite the shader code to fit an "ancient" graphics
card, so we simply fall back to the GL 1 engine.

Reviewed-by: Trond
(cherry picked from commit 33ed3d0bacddce214a43be60eb6481903e753a88)
(cherry picked from commit bd94c6df873ab196e537f5a49b57c86ccd66ad90)

pruiz/wkhtmltopdf-qt,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,radekp/qt,radekp/qt,igor-sfdc/qt-wk,igor-sfdc/qt-wk,igor-sfdc/qt-wk,radekp/qt,radekp/qt,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,radekp/qt,radekp/qt,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,igor-sfdc/qt-wk,radekp/qt,igor-sfdc/qt-wk,igor-sfdc/qt-wk,radekp/qt,pruiz/wkhtmltopdf-qt,radekp/qt,pruiz/wkhtmltopdf-qt,radekp/qt,igor-sfdc/qt-wk,igor-sfdc/qt-wk