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

searchform.php

@@ -1,5 +1,5 @@
-<form role="search" method="get" id="searchform" action="<?php echo home_url('/'); ?>">
+<form role="search" method="get" id="searchform" class="form-search <?php if (is_404() || !have_posts()) { ?> well <?php } ?>" action="<?php echo home_url('/'); ?>">
   <label class="visuallyhidden" for="s"><?php _e('Search for:', 'roots'); ?></label>
-  <input type="text" value="" name="s" id="s" placeholder="<?php _e('Search', 'roots'); ?> <?php bloginfo('name'); ?>">
-  <input type="submit" id="searchsubmit" value="<?php _e('Search', 'roots'); ?>" class="button">
-</form>
+  <input type="text" value="" name="s" id="s" class="search-query" placeholder="<?php _e('Search', 'roots'); ?> <?php bloginfo('name'); ?>">
+  <input type="submit" id="searchsubmit" value="<?php _e('Search', 'roots'); ?>" class="btn">
+</form>