tests joined and made workable with MiniKdc
1) miniKdc changed to version 2.0.0-M16 to have kinit in client part;
2) added method to MiniKdc to create users with specified passwords.
Merge branch 'fb-HADOOP-9166-trunk-gd' of https://github.com/griddynamics/yhadoop-common into fb-HADOOP-9166-trunk-gd