404 and 500 page ui

templates/status/404.tmpl

@@ -1,7 +1,8 @@
 {{template "base/head" .}}
 {{template "base/navbar" .}}
-<div id="gogs-body" class="container">
-    <h4>This page is not found !</h4>
+<div id="gogs-body" class="container text-center">
+    <p style="margin-top: 80px"><img src="/img/404.png" alt="404"/></p>
+    <hr/>
     <p>Application Version: {{AppVer}}</p>
 </div>
 {{template "base/footer" .}}

templates/status/500.tmpl

@@ -1,7 +1,10 @@
 {{template "base/head" .}}
 {{template "base/navbar" .}}
-<div id="gogs-body" class="container">
+<div id="gogs-body" class="container text-center">
+    <p style="margin-top: 80px"><img src="/img/500.png" alt="404"/></p>
+    <hr/>
     <p>An error is occurred : {{.ErrorMsg}}</p>
+    <hr/>
     <p>Application Version: {{AppVer}}</p>
 </div>
 {{template "base/footer" .}}