Bug fix: non square cursors were drawn improperly.

src/cursor.js

@@ -126,7 +126,7 @@ SpiceCursorConn.prototype.process_channel_message = function(msg)
 
 SpiceCursorConn.prototype.set_cursor = function(cursor)
 {
-    var pngstr = create_rgba_png(cursor.header.height, cursor.header.width, cursor.data);
+    var pngstr = create_rgba_png(cursor.header.width, cursor.header.height, cursor.data);
     var curstr = 'url(data:image/png,' + pngstr + ') ' +
         cursor.header.hot_spot_x + ' ' + cursor.header.hot_spot_y + ", default";
     var screen = document.getElementById(this.parent.screen_id);