option: sort a wordlist by mask, then by natural sort order

[roycewilliams]

It would be very useful to be able to sort a wordlist first by length, then by mask, then by natural sort order.

Example:

2345
z5678
1234
C5309
9999a
2345a
1234a
!6666
z9933
a1234

... would sort as:

1234
2345
1234a
2345a
9999a
a1234
z5678
z9933
C5309
!6666

Suggested mask order: ?d?l?u?s, to match the rough order of frequency groups.

It would be useful for this option to support sorting both raw wordlists and potfiles. Automatic interpretation of $HEX would also be good.