Improve SEO by pre-rendering all HTML pages

* Change all internal links to use URLs ending in `/`
* Add the prerender script which uses PhantomJS to pre-render the
  HTML for all possible pages in the system
* Change the build process to incorporate the pre-rendered files
* Update the sitemap script to generate the new URLs

src/pages/includes/_footer.jade

@@ -32,5 +32,5 @@
         .action
             iframe(src="http://ghbtns.com/github-btn.html?user=andrewminer&repo=crafting-guide&type=fork&size=large",
               allowtransparency="true", frameborder="0", scrolling="0", width="100", height="32")
-    a(href="/test.html")
+    a(href="/test.html", rel="nofollow")
         .divider.bottom

src/pages/includes/_header.jade

@@ -17,12 +17,12 @@
         a(data-page="home", href="/")
             p Home
             .dot
-        a(data-page="configure", href="/configure")
+        a(data-page="configure", href="/configure/")
             p Configure
             .dot
-        a(data-page="browse", href="/browse")
+        a(data-page="browse", href="/browse/")
             p Browse
             .dot
-        a(data-page="craft", href="/craft")
+        a(data-page="craft", href="/craft/")
             p Craft
             .dot