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

css/less/hero-unit.less

@@ -0,0 +1,20 @@
+// HERO UNIT
+// ---------
+
+.hero-unit {
+  padding: 60px;
+  margin-bottom: 30px;
+  background-color: #f5f5f5;
+  .border-radius(6px);
+  h1 {
+    margin-bottom: 0;
+    font-size: 60px;
+    line-height: 1;
+    letter-spacing: -1px;
+  }
+  p {
+    font-size: 18px;
+    font-weight: 200;
+    line-height: @baseLineHeight * 1.5;
+  }
+}