Test that each of the eight EXIF orientations is applied to the transformed image appropriately.

Test that EXIF orientation and any additional transforms don't conflict. This is tested with orientation=7, which involves both a rotation and a flip,

TimeoutHandler returns a Handler that runs h with the given time limit. The new Handler calls h.ServeHTTP to handle each request, but if a call runs

serveImage handles incoming requests for proxied images.