niklasvh/html2canvas — pull request #374 by nqtien310 (2014-04-20 05:45:27+00:00)
Title: Fix cross origin images ( Such as S3 )  are failed to load on iPhone Safari

iPhone Safari's caching mechanism somehow makes CORS images failed to be loaded, I just suspect that its caching request is missing the origin header which cause the error Cross Origin Not Allowed

Adding timestamp to burn the cache fix it right away