The PDPageContentStream class has two drawImage methods (one calling the other) but both add a transformation to the graphics state. This patch adds a drawImage method with a single parameter (the image), which only adds the image without applying any transformation.
This is needed because otherwise there is no other way of setting a transform matrix manually which might have skew/rotation in addition to scaling/translation.
An alternative to this patch could also be a drawImage method which takes a Matrix and applies it. But still if for whatever reasons multiple images should be drawn with the same transformation matrix this would be inflexible.