Test 0:
    The example text in the vdelta paper.  Use target only, no source.

Test 1:
    The insertion of "xxxx" in between `l' and `m' in the alphabet.

Test 2:
    Transposition of the alphabet around the point between `l' and `m'.

Test 3:
    Insertion of `x' after `d', and another after `t'.

Test 4:
    Insertion of `x' after `c' (not yet 4 bytes!), and another after `t'.

Test 5:
    Random text, no relation to source.