Fixes #5140: visudo on Debian 6 cannot use strict mode
Fixes #5149: Fixes detection of no group name, no password or no fullname in usermanagement
Merge pull request #432 from ncharles/bug_5149/dev/empty_group_detection_is_broken

Fixes #5149: Fixes detection of no group name, no password or no fullnam...
Fixes #5136: fix typos in class name for detecting OS version in OpenSSH Server technique
Merge pull request #428 from ncharles/bug_5136/dev/correct_class_names

Fixes #5136: fix typos in class name for detecting OS version in OpenSSH...
Merge pull request #429 from ncharles/bug_5140/dev/fix_sudo_on_1_7_4

Fixes #5140: visudo on Debian 6 cannot use strict mode
Merge branch 'branches/rudder/2.6' into branches/rudder/2.9