remove inset shadow from disabled buttons

lib/patterns.less

@@ -422,6 +422,7 @@ footer {
     cursor: default;
     background-image: none;
     .opacity(65);
+    .box-shadow(none);
   }
   &:disabled {
     // disabled pseudo can't be included with .disabled

lib/scaffolding.less

@@ -69,7 +69,6 @@ body {
   margin: 0;
   #font > .sans-serif(normal,@basefont,@baseline);
   color: @gray;
-  text-rendering: optimizeLegibility;
 }
 
 // Container (centered, fixed-width layouts)
@@ -107,4 +106,4 @@ a {
     color: @linkColorHover;
     text-decoration: underline;
   }
-}
+}