fixes #4442: allow for .btn within a .btn-toolbar without .btn-group

docs/assets/css/bootstrap.css

@@ -3328,6 +3328,7 @@ input[type="submit"].btn.btn-mini {
 .btn-toolbar {
   margin-top: 10px;
   margin-bottom: 10px;
+  font-size: 0;
 }
 
 .btn-toolbar .btn-group {
@@ -3338,6 +3339,11 @@ input[type="submit"].btn.btn-mini {
   *zoom: 1;
 }
 
+.btn-toolbar .btn-group + .btn,
+.btn-toolbar .btn + .btn-group {
+  margin-left: 5px;
+}
+
 .btn-group > .btn {
   position: relative;
   margin-left: -1px;

less/button-groups.less

@@ -18,12 +18,17 @@
 
 // Optional: Group multiple button groups together for a toolbar
 .btn-toolbar {
+  font-size: 0; // Hack to remove whitespace that results from using inline-block
   margin-top: @baseLineHeight / 2;
   margin-bottom: @baseLineHeight / 2;
   .btn-group {
     display: inline-block;
     .ie7-inline-block();
   }
+  .btn-group + .btn,
+  .btn + .btn-group {
+    margin-left: 5px;
+  }
 }
 
 // Float them, remove border radius, then re-add to first and last elements