Add jsdoc and pass through other params

lib/client.js

@@ -692,13 +692,23 @@ MatrixClient.prototype.setAvatarUrl = function(url, callback) {
     );
 };
 
-MatrixClient.prototype.getAvatarUrlForMember = function(member, width, height, resizeMethod) {
+/**
+ * Get the avatar URL for a room member.
+ * @param {module:room-member.RoomMember} member
+ * @param {Number} width The desired width of the thumbnail.
+ * @param {Number} height The desired height of the thumbnail.
+ * @param {string} resizeMethod The thumbnail resize method to use, either
+ * "crop" or "scale".
+ * @return {?string} the avatar URL or null.
+ */
+MatrixClient.prototype.getAvatarUrlForMember =
+        function(member, width, height, resizeMethod) {
     if (!member.events.member) {
         return null;
     }
     var rawUrl = member.events.member.getContent().avatar_url;
     if (rawUrl) {
-        return this._http.getHttpUriForMxc(rawUrl);
+        return this._http.getHttpUriForMxc(rawUrl, width, height, resizeMethod);
     }
     return null;
 };