Respect iterations in RAR 5 format. Hash re-extraction is required.
Merge pull request #722 from kholia/RAR5-fixes

Respect iterations in RAR 5 format. Hash re-extraction is required.
Fix a problem with --skip-self-test
Drop the "alleged" from RAR5 algorithm name. It actually is
PBKDF2. Also fix some bugs and comments in valid().
RAR5 valid() had a test done twice.
Add documentation for cracking Apple DMG files