Respect the pad byte required when chunk data has an odd number of bytes

[operator1]

From the Audio IFF spec:

"ckData contains the data stored in the chunk. The format of this data is determined by ckID. If
the data is an odd number of bytes in length, a zero pad byte must be added at the end. The pad
byte is not included in ckSize ."

I don't think this pad byte is respected at the moment.