Fixes #799 issue with reveal fix for hidden content selectability breaking animation in chrome in 0.15.5

src/elements/reveal.less

@@ -62,9 +62,6 @@
   z-index: 3 !important;
 }
 
-.ui.reveal:hover > .hidden.content {
-  z-index: 5 !important;
-}
 
 /*------------------
    Loose Coupling
@@ -215,14 +212,28 @@
       Fade
 ---------------*/
 
-.ui.fade.reveal > .visible.content {
-  opacity: 1;
+.ui.fade.reveal > .hidden.content {
+  -webkit-transition:
+    opacity 0.8s cubic-bezier(0.175, 0.885, 0.320, 1) 0.15s
+  ;
+  -moz-transition:
+    opacity 0.8s cubic-bezier(0.175, 0.885, 0.320, 1) 0.15s
+  ;
+  -ms-transition:
+    opacity 0.8s cubic-bezier(0.175, 0.885, 0.320, 1) 0.15s
+  ;
+  transition:
+    opacity 0.8s cubic-bezier(0.175, 0.885, 0.320, 1) 0.15s
+  ;
 }
-.ui.fade.reveal:hover > .visible.content,
-.ui.fade.reveal:focus > .visible.content {
+
+.ui.fade.reveal > .hidden.content {
+  z-index: 5 !important;
   opacity: 0;
 }
-
+.ui.fade.reveal:hover > .hidden.content {
+  opacity: 1;
+}
 
 /*--------------
       Move