#2 Successful 2img processing with optional chunks

[David Schmidt]

The processing for 2img files is broken for 2imgs that
have optional stuff at the end. There is a hardcoded
assumption that 2img files have exactly 64 bytes of
header. Unforutnately, you can have several optional
chunks at the end as well. I wrote a patch (probably
not the ideal, but...) that just looks for the 2IMG
signature and calls that a 2img image. Works for me!

[David Schmidt]

Recognizing 2imgs with optional chunks