In fact i like my idea of using iterations.
I have some time tomorrow, so if nobody complains until then,
i write diffs for the tests of 3.x and 2.7 with these updates:

- Two different target sizes:
    1. 0xFFFFFFFF + x (7)
    2. 0x7FFFFFFF + x (7)
- On 32 bit systems, use iterations on a potentially safe buffer
  size.  I think 0x40000000 a.k.a 1024*1024*1024 is affordable,
  but 512 MB are probably more safe?  I'll make that a variable.
- The string will be 'DeadAffe' (8).
- The last 4 bytes of the string will always be read on their own
  (just in case the large buffer sizes irritated something down
  the path).