Speed up texture uploads for hardware without n-pot-2 texture support.
Speed up texture uploads for hardware without n-pot-2 texture support.

Implement a manual fast scale, so that we can do a scale, swizzle and
mirror in the same loop without any temporary image copies.
This potentially increases texture uploads on embedded hw with a factor
of 10.

Reviewed-by: Samuel

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