Theme: Disabled elements can still be focused with a click

pointer-events: none; fixes this in chrome, safari, and firefox.
IE and opera both show no focus styles on click, so lack of
pointer-events support in old ie is not a problem.

Fixes #10573
Closes gh-1330

themes/base/core.css

@@ -62,6 +62,7 @@
 ----------------------------------*/
 .ui-state-disabled {
 	cursor: default !important;
+	pointer-events: none;
 }