add post editing

views/post/single-post.etlua

@@ -0,0 +1,9 @@
+<% if not post then %>
+  <% render("views.common.infobox", {kind = constants.InfoboxKind.ERROR, msg = "Post not found"}) %>
+<% else %>
+  <div class=darkbg>
+    <h1 class=thread-title><%= post.username .. "'s post in " .. thread.title %></h1>
+  </div>
+  <% render("views.threads.post", {post = post, edit = false, is_latest = false, no_reply = true}) %>
+  <a class=linkbutton href="<%= url_for("thread", {slug = thread.slug}, {after = post.id}) .. "#post-" .. post.id %>">View in context</a>
+<% end %>