Reset the box model to content-box in the web debug toolbar

This makes the styles compatible with CSS frameworks changing the box
model to box-sizing using a universal selector (Bootstrap 3 for instance).

src/Symfony/Bundle/WebProfilerBundle/Resources/views/Profiler/toolbar.css.twig

@@ -18,6 +18,12 @@
     z-index: 6000000;
 }
 
+.sf-toolbarreset * {
+    -webkit-box-sizing: content-box;
+    -moz-box-sizing: content-box;
+    box-sizing: content-box;
+}
+
 .sf-toolbarreset {
     position: fixed;
     background-color: #f7f7f7;