Integer representation

[meepbear *]

>00 80 00 is what you want. The reason being that in two's complement,
>80 00 is -0x7fff.
The problem was that Perl apparently expects word-multiple bigints and I was 
simply encoding bytes.
0x450 doesn't have its highest bit set but still needs to be padded to 
"0450".

The spec needs altering in that case since currently it says "shortest" 
while it should be "shortest word-multiple".

In any event, the consumer verifies the token each and every time now so I'm 
happy :).