Validates that C<name> is a valid username.
+=item configuration()
+
+Returns a hashref containing runtime configuration information. Contains these fields:
+
+=over
+
+=item base_path
+
+The base path to the Blërg database
+
+=item data_path
+
+The path under base_path for account data
+
+=item hash_tags_path
+
+The path under base_path for hashtag data
+
+=item ref_tags_path
+
+The path under base_path for mention data
+
+=back
+
=back
=head2 AUTHENTICATION
Returns 1 if the session is valid, 0 otherwise. Also resets the expiration
time of the session.
+=item auth_get_counter(username)
+
+Gets an opaque "counter" value for the auth information of the given username.
+This counter is changed every time the authentication information is changed,
+making it useful for protecting password changes against replay attacks.
+Returns a 32-bit integer on success, or undef on failure.
+
=back
=head1 CONSTRUCTOR