Allow items to be filtered via itemsSelector when target is self

[sorvell]

polymer-ui-menu extends polymer-selector and the selector target is the menu itself. It would be useful to be able to locate the menu items as other than direct children of the menu. The itemsSelector property is intended for this use but it only works if the selector targets another element.

This would be useful for this type of construction:

<polymer-ui-menu>
  <a><polymer-ui-menu-item></polymer-ui-menu-item></a>
 ...

See this thread for more info: https://groups.google.com/forum/#!topic/polymer-dev/CTumvA_cTtE

[sjmiles]

Fwiw, another possibility is to have a followLinks feature (or something) in menu-item that causes taps to behave roughly like this:

var a = this.querySelector('a');
window.location.href = a.href;