title: material design selectbox polymer
body: <p>I noticed there were no "selectbox" widgets within the Paper Elements section of Polymer documentation, nor did I see one in the Polymer GitHub repos.  Also I don't recall seeing any specific guidance on the Material Design specifications as to how a selectbox should look or behave.</p>
  
  <p>Are there proposals out there?  Or specific plans to incorporate designs for selectboxes within material design / polymer paper elements?</p>
  
  <p>I definitely understand that you can basically get the same functionality from checkboxes (multi) or radio buttons (single), but from an aesthetic perspective, depending on the specific application, I get the feeling it may be a good idea to have 'select' available as an option.</p>