Support resolved in juju-gui env

[Gary Poster]

    /**
     * Mark the given unit or relation problem as resolved.
     *
     * @method resolved
     * @param {String} unit_name The unit name.
     * @param {String} relation_name The relation name.
     * @param {Boolean} retry Whether or not to retry the unit/relation.
     * @param {Function} callback A callable that must be called once the
         operation is performed.
     * @return {undefined} Sends a message to the server only.
     */
    resolved: function(unit_name, relation_name, retry, callback) {
      this._send_rpc({
        op: 'resolved',
        unit_name: unit_name,
        relation_name: relation_name || null,
        retry: retry || false}, callback, true);
    },