Added option to disable comments on individual pages/posts

Disable comments on an individual page/post by setting `nocomments:
true` in the front matter

exampleSite/content/page/about.md

@@ -2,6 +2,7 @@
 layout: page
 title: About me
 subtitle: Why you'd want to go on a date with me
+nocomments: false # set true to disable comments on this page
 ---
 
 My name is Inigo Montoya. I have the following qualities:

layouts/partials/disqus.html

@@ -1,4 +1,4 @@
-{{ if .Site.DisqusShortname }}
+{{ if and .Site.DisqusShortname (not .Params.nocomments) }}
     <div class="comments">
         {{ template "_internal/disqus.html" . }}
     </div>

layouts/partials/page.html

@@ -2,7 +2,7 @@
   <div class="row">
     <div class="col-lg-8 col-lg-offset-2 col-md-10 col-md-offset-1">
       {{ .Content }}
-      {{ if .Site.DisqusShortname }}
+      {{ if and .Site.DisqusShortname (not .Params.nocomments) }}
         <div class="disqus-comments">
         {{ template "_internal/disqus.html" . }}
         </div>

layouts/partials/post.html

@@ -18,7 +18,7 @@
         {{ end }}
       </ul>
 
-      {{ if .Site.DisqusShortname }}
+      {{ if and .Site.DisqusShortname (not .Params.nocomments) }}
       <div class="disqus-comments">
         {{ template "_internal/disqus.html" . }}
       </div>