add html5 invalid state for super fancy errors via browser

lib/forms.less

@@ -299,6 +299,19 @@ textarea[readonly] {
   .formFieldState(#468847, #57a957, lighten(#57a957, 30%));
 }
 
+// HTML5 invalid states
+// Shares styles with the .control-group.error above
+input:invalid,
+textarea:invalid,
+select:invalid {
+  color: #b94a48;
+  border-color: #ee5f5b;
+  &:focus {
+    border-color: darken(#ee5f5b, 10%);
+    .box-shadow(0 0 6px lighten(#ee5f5b, 20%));    
+  }
+}
+
 
 
 // FORM ACTIONS