some relbench improvements and adjustments

Using benchmark-unify is only useful if there really is a chance
that this might increase the number of benchmarks being compared.
So the tests were improved, to exclude cases where one file had
"Many salts" and "Only one salt", and the other just "Raw"
for the same format.

Recent changes in john's test output caused some "Could not parse"
errors, so the parsing has been adjusted.
Parsing has also been adjusted to handle dynamic formats using
brackets in their expression, resulting in nested brackets [ [  ] ]
in --test output.

The list of formats that exist only in one of the files is now
sorted by name.
When using -v, the ratio output is also sorted by name.
(Dynamic formats will not just be sorted alphabetically, but by
dynamic format number.)