CSS: Ignore the CSS cascade in show()/hide()/etc.

Fixes gh-1767
Fixes gh-2071
Closes gh-2180

(cherry picked from commit 86419b10bf)

Conflicts:
	src/css.js
	src/css/defaultDisplay.js
	src/effects.js
	test/data/testsuite.css
	test/unit/css.js
	test/unit/effects.js

test/data/testsuite.css

@@ -76,7 +76,8 @@ div.noopacity {
 	-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(opacity=0)";
 }
 
-div.hidden {
+div.hidden,
+span.hidden {
 	display: none;
 }
 
@@ -124,10 +125,6 @@ div#fx-tests div.noback {
 	display: none;
 }
 
-/* tests to ensure jQuery can determine the native display mode of elements
-   that have been set as display: none in stylesheets */
-div#show-tests * { display: none; }
-
 #nothiddendiv { font-size: 16px; }
 #nothiddendivchild.em { font-size: 2em; }
 #nothiddendivchild.prct { font-size: 150%; }
@@ -135,11 +132,6 @@ div#show-tests * { display: none; }
 /* For testing type on vml in IE #7071 */
 v\:oval { behavior:url(#default#VML); display:inline-block; }
 
-/* 8099 changes to default styles are read correctly */
-tt { display: none; }
-sup { display: none; }
-dfn { display: none; }
-
 /* #9239 Attach a background to the body( avoid crashes in removing the test element in support ) */
 body, div { background: url(http://static.jquery.com/files/rocker/images/logo_jquery_215x53.gif) no-repeat -1000px 0; }