Remove all frameworks except Bootstrap (#251)

- Remove all frameworks except Bootstrap

- Remove roots-options.php and replace with a more simple
  roots-config.php

- Include all Bootstrap Javascript plugins by default in
  js/plugins.js

- Use Bootstrap Responsive and Topbar navigation by default

- Use Bootstrap markup on forms, page titles, image galleries,
  alerts and errors, post and comment navigation

- Remove Roots styles from style.css and introduce app.css for
  site-specific CSS. Remove almost all previous default Roots
  styles.

- Add latest updates from H5BP project

404.php

@@ -1,21 +1,24 @@
 <?php get_header(); ?>
   <?php roots_content_before(); ?>
-    <div id="content" class="<?php echo $roots_options['container_class']; ?>">
+    <div id="content" class="<?php echo CONTAINER_CLASSES; ?>">
     <?php roots_main_before(); ?>
-      <div id="main" class="<?php echo $roots_options['fullwidth_class']; ?>" role="main">
-        <div class="container">
+      <div id="main" class="<?php echo FULLWIDTH_CLASSES; ?>" role="main">
+        <div class="page-header">
           <h1><?php _e('File Not Found', 'roots'); ?></h1>
-          <p><?php _e('The page you are looking for might have been removed, had its name changed, or is temporarily unavailable.', 'roots'); ?></p>
-          <p><?php _e('Please try the following:', 'roots'); ?></p>
-          <ul>
-            <li><?php _e('Check your spelling', 'roots'); ?></li>
-            <li><?php printf(__('Return to the <a href="%s">home page</a>', 'roots'), home_url()); ?></li>
-            <li><?php _e('Click the <a href="javascript:history.back()">Back</a> button', 'roots'); ?></li>
-          </ul>
-          <?php get_search_form(); ?>
         </div>
+        <div class="alert alert-block fade in">
+          <a class="close" data-dismiss="alert">×</a>
+          <p><?php _e('The page you are looking for might have been removed, had its name changed, or is temporarily unavailable.', 'roots'); ?></p>
+        </div>
+        <p><?php _e('Please try the following:', 'roots'); ?></p>
+        <ul>
+          <li><?php _e('Check your spelling', 'roots'); ?></li>
+          <li><?php printf(__('Return to the <a href="%s">home page</a>', 'roots'), home_url()); ?></li>
+          <li><?php _e('Click the <a href="javascript:history.back()">Back</a> button', 'roots'); ?></li>
+        </ul>
+        <?php get_search_form(); ?>
       </div><!-- /#main -->
     <?php roots_main_after(); ?>
     </div><!-- /#content -->
   <?php roots_content_after(); ?>
-<?php get_footer(); ?>
+<?php get_footer(); ?>