Metacat

Add users which are needed in the junit tests when the metacat is file-based authentication.
If users have been added, it just print out the exception.

Change the test file according to the change on the constructor.

Made changes according the changes in the AuthFile class.

Add the test method for the getUserInfo method.

Modified the junit test file according to the change in the class.

Change the test file according to the change made in the class.

Change the addGroup method since the API was changed.

Add the test method for the getPrincipals.

Add test methods for changing passwords.

Add method to test the getusers method.