Handle NUL-terminated ASCII strings.

[maltoe]

Hi @remvee

I admit I have no real idea of what I'm doing here as I did not read any EXIF specs or anything so far. Just came across a few JPEG files created by the GoPro HD2 where the make, model, and software tags returned some garbage after the actual value (as returned by other exif readers / exiv2). I assume GoPro is using the remaining bytes internally somehow since it does not look like a valid string in any encoding to me, and also not like encoding information.

The easy fix is to strip the strings after the NUL terminator, so unpack('Z*'). The change feels a bit dangerous, but all tests still pass and who am I to say this. Happy to come up with a "proper" solution if you point me to in the right direction.

Malte

[remvee]

Thank you for this changeset!