Merge branch '2.2.2-wip' into exploratory

Conflicts:
	docs/assets/css/bootstrap.css
	less/buttons.less
	less/forms.less

less/forms.less

@@ -388,9 +388,9 @@ input[type="checkbox"][readonly] {
 
 // HTML5 invalid states
 // Shares styles with the .control-group.error above
-input:focus:required:invalid,
-textarea:focus:required:invalid,
-select:focus:required:invalid {
+input:focus:invalid,
+textarea:focus:invalid,
+select:focus:invalid {
   color: #b94a48;
   border-color: #ee5f5b;
   &:focus {
@@ -489,7 +489,8 @@ select:focus:required:invalid {
     border: 1px solid #ccc;
   }
   .add-on,
-  .btn {
+  .btn,
+  .btn-group > .dropdown-toggle {
     vertical-align: top;
     border-radius: 0;
   }
@@ -516,7 +517,8 @@ select:focus:required:invalid {
   select,
   .uneditable-input {
     border-radius: @inputBorderRadius 0 0 @inputBorderRadius;
-    + .btn-group .btn {
+    + .btn-group .btn,
+    + .btn-group .btn:last-child {
       border-radius: 0 @inputBorderRadius @inputBorderRadius 0;
     }
   }
@@ -526,7 +528,8 @@ select:focus:required:invalid {
     margin-left: -1px;
   }
   .add-on:last-child,
-  .btn:last-child {
+  .btn:last-child,
+  .btn-group:last-child > .dropdown-toggle {
     border-radius: 0 @inputBorderRadius @inputBorderRadius 0;
   }
 }