Enable responsive features in IE10 when snapped

docs/assets/css/bootstrap-responsive.css

@@ -8,6 +8,10 @@
  * Designed and built with all the love in the world @twitter by @mdo and @fat.
  */
 
+@-ms-viewport {
+  width: device-width;
+}
+
 .clearfix {
   *zoom: 1;
 }

less/responsive.less

@@ -14,6 +14,14 @@
 // -------------------------------------------------------------
 
 
+// IE10 Metro responsive
+// Required for Windows 8 Metro split-screen snapping with IE10
+
+@-ms-viewport{
+  width: device-width;
+}
+
+
 // REPEAT VARIABLES & MIXINS
 // -------------------------
 // Required since we compile the responsive stuff separately