This commit contains bugfixes for authentication within metadata-server.pl and related perl code, and is committed separately before changes in gsajaxapi.js start to make use of it. Another important change is that for adding user comments, a user need not be in the collection's group, so checking the group shouldn't be performed. The bugfixes are to get the authentication to work and are in addition to an earlier commit that corrected the name of the authentication_enable variable in baseaction.pm. The bugfixes are: users.gdb instead of users.db, metadata-server.pl needs to call gsdlCGI's encrypt_password otherwise the password check will fail because it won't match with what's in the db. Also, the calls to authenticate_user had to be through the self variable, since its a method not a function and failed to work correctly otherwise.
