[CON-73] Deprecate useradmin CLI in favor of something that is more sensible
[CON-73] add comment for hasUser in ConcourseServerMXBean
[CON-73] minor refactoring: move validators to AccessManger & put back deprecated params with deprecated messages
[CON-73] enhance javadoc
[CON-73] refactoring to use internal username/password validator of AccessManager
Merge remote-tracking branch 'upstream/develop' into develop
Merge remote-tracking branch 'upstream/develop' into develop
change warning messages from stdout output to console read and wait for user action
Merge pull request #11 from knd/develop

[CON-73] Deprecate useradmin CLI in favor of something that is more sens...