Add support for cracking Siemens S7 authentication protocol hashes

Signed-off-by: Dhiru Kholia <dhiru@openwall.com>
Signed-off-by: Narendra Kangralkar <narendrakangralkar@gmail.com>
Merge pull request #193 from kholia/siemens-s7

Add support for cracking Siemens S7 authentication protocol hashes