update(autocomplete): fixes somewhat major bug introduced in RC3 wher…

…e autocomplete was not functioning at all

This was due to the scroll lock being a bit too aggressive.  Fixed the logic in scroll lock.

src/core/util/util.js

@@ -56,7 +56,8 @@ angular.module('material.core')
 
       // Creates a virtual scrolling mask to absorb touchmove, keyboard, scrollbar clicking, and wheel events
       function disableElementScroll() {
-        var zIndex = $window.getComputedStyle(element[0]).zIndex;
+        var zIndex = $window.getComputedStyle(element[0]).zIndex - 1;
+        if (isNaN(zIndex)) zIndex = 99;
         var scrollMask = angular.element(
             '<div class="md-scroll-mask" style="z-index: ' + zIndex + '">' +
             '  <div class="md-scroll-mask-bar"></div>' +
@@ -79,6 +80,8 @@ angular.module('material.core')
         // used to stop the keypresses that could cause the page to scroll
         // (arrow keys, spacebar, tab, etc).
         function disableKeyNav(e) {
+          //-- temporarily removed this logic, will possibly re-add at a later date
+          return;
           if (!element[0].contains(e.target)) {
             e.preventDefault();
             e.stopImmediatePropagation();