Hyde theme: sync with upstream to v2.0.0.

CSS is now split into poole.css and hyde.css; chrome/sidebar.html updated.

Also cherry-pick:

  * poole/hyde@48b9d1f - Set a max-width for images

layouts/chrome/head.html

@@ -10,6 +10,7 @@
   <title> {{ .Title }} &middot; {{ .Site.Title }} </title>
 
   <!-- CSS -->
+  <link rel="stylesheet" href="{{ .Site.BaseUrl }}/css/poole.css">
   <link rel="stylesheet" href="{{ .Site.BaseUrl }}/css/syntax.css">
   <link rel="stylesheet" href="{{ .Site.BaseUrl }}/css/hyde.css">
   <link rel="stylesheet" href="http://fonts.googleapis.com/css?family=PT+Sans:400,400italic,700|Abril+Fatface">

layouts/chrome/sidebar.html

@@ -1,19 +1,19 @@
-    <header class="masthead">
-      <div class="masthead-inner">
+<div class="sidebar">
+  <div class="container sidebar-sticky">
+    <div class="sidebar-about">
       <h1>{{ .Site.Title }}</h1>
       <p class="lead">
       {{ with .Site.Params.Description }} {{.}} {{ else }}An elegant open source and mobile first theme for <a href="http://hugo.spf13.com">hugo</a> made by <a href="http://twitter.com/mdo">@mdo</a>. Originally made for Jekyll.{{end}}
       </p>
+    </div>
 
-        <div class="colophon">
-          <ul class="colophon-links">
-              <li><a href="/">Home</a> </li>
-              {{ range .Site.Menus.main }}
-                    <li><a href="{{.Url}}"> {{ .Name }} </a></li>
-              {{end}}
-          </ul>
+    <ul class="sidebar-nav">
+      <li><a href="/">Home</a> </li>
+      {{ range .Site.Menus.main }}
+        <li><a href="{{.Url}}"> {{ .Name }} </a></li>
+      {{end}}
+    </ul>
 
-          <p>{{ with .Site.Params.Copyright }}{{.}}{{ else }}&copy; {{.Now.Format "2006"}}. All rights reserved. {{end}}</p>
-        </div>
-      </div>
-    </header>
+    <p>{{ with .Site.Params.Copyright }}{{.}}{{ else }}&copy; {{.Now.Format "2006"}}. All rights reserved. {{end}}</p>
+  </div>
+</div>