Add charset definition to HTML pages

Specifying the charset prevents the browser from guessing the charset to
use.

Relates to innoq#130.

src/statuses/views/layout.clj

@@ -27,6 +27,7 @@
   ([title username content footer]
    (html5
      [:head
+      [:meta {:charset "utf-8"}]
       [:meta {:name "viewport"
               :content "width=device-width, initial-scale=1.0, maximum-scale=1, user-scalable=no"}]
       [:title (str title " - innoQ Statuses")]