Removed skip macro T.

T was essentially redundant. We can skip n bits using the read macro A
and just ignore the return value. Note that T(48); needed to be
changed into A(24);A(24); because the input buffer is only 32 bits
wide. There is still a significant reduction in character count as we
completely removed T's definition.
Post increment mayhem.

- #define N(n)p[a]=n;a++;if(a==37268)I();
+ #define N(n)p[a++]=n;if(a==37268)I();

- p[a]=p[c];a++;c++;
+ p[a++]=p[c++];
Removed sign mask when storing a literal.

There is no need for the sign mask here (assuming valid input) as we
have already checked that o>256.

if(o<256){N(o&255);...

if(o<256){N(o);...
Moved test script to t/