fix($StateRefDirective): fix anchor check flaw angular-ui#1667

Fix the tagName comparism to make ui-sref also work inside an SVG.

Author: martinoss

src/stateDirectives.js

@@ -86,7 +86,7 @@ function $StateRefDirective($state, $timeout) {
     link: function(scope, element, attrs, uiSrefActive) {
       var ref = parseStateRef(attrs.uiSref, $state.current.name);
       var params = null, url = null, base = stateContext(element) || $state.$current;
-      var newHref = null, isAnchor = element.prop("tagName") === "A";
+      var newHref = null, isAnchor = element.prop("tagName").toUpperCase() === "A";
       var isForm = element[0].nodeName === "FORM";
       var attr = isForm ? "action" : "href", nav = true;