[Caja] support a.hash (issue 5694073)

[felix8a]

Reviewers: metaweta, Jasvir,

Description:
jquery.ui.tabs expects <a> elements to have a .hash property, which
isn't in the html4 spec but is in html5, and it's supported by all
browsers that I tried (including ie6).

Please review this at http://codereview.appspot.com/5694073/

Affected files:
  M     src/com/google/caja/plugin/domado.js


Index: src/com/google/caja/plugin/domado.js
===================================================================
--- src/com/google/caja/plugin/domado.js        (revision 4785)
+++ src/com/google/caja/plugin/domado.js        (working copy)
@@ -3387,6 +3387,7 @@
         names: ['a'],
         domClass: 'HTMLAnchorElement',
         properties: {
+          hash: NP.filter(false, identity, true, identity),
           href: NP.filter(false, identity, true, identity)
         }
       });