Tutorial improvements

- Skip the build-related tutorial steps when builds are disabled
- Make the styling of the tutorial more consistent with the new layout

static/tutorial/create-container.html

@@ -14,7 +14,7 @@ CONTAINER ID        IMAGE               COMMAND             CREATED
 <var class="var1">07f2065197ef</var>          ubuntu:12.04        echo fun            31 seconds ago
 </pre>
 
-<div class="alert alert-info">
+<div class="user-enter-box">
   <div class="control-group">
     <label class="control-label" for="containerId">Enter the container ID returned:</label>
     <div class="form-inline">