if the %pdf version header comment is offset from the start of the file the cross reference offsets will also be wrong by that amount. this change updates the cross reference location logic to use the offset from the located version header.
since inline image data may contain the end image "ei" token inside the data stream there's no reliable way to actually determine if we've read all the data. for this reason if we end up with an invalid state parsing operations after we've read the end image token we try to recover by reading from the previous token to the next end image token if any. we supply log information to let the consumer know this is what we're doing. it's still not bullet-proof but it should be good enough.
also support negative page rotation values by adding them to a 360 degree rotation so -90 degrees clockwise is 270 degrees clockwise.
