drawings not supported

[maxandersen]

InlineDrawing has no public api for converting it to an image.

Bug at google: https://code.google.com/p/google-apps-script-issues/issues/detail?id=3367

Wonder if could copy the drawing to temporay document and export it to HTML content which would then create a zip with images folder having just this document.

[maxandersen]

stackoverflow article hinting at how to do it by exporting to pdf http://stackoverflow.com/questions/19736068/how-do-i-export-inlinedrawing-as-an-image-in-document