Add tor video routing

Includes non-tor video routing by default, so no more chances
of the browser leaking headers or user agent to googlevideo
Adjust settings upgrade system to facilitate change to route_tor
setting.
Add some more space on settings page for dropdown settings so does
not overflow due to options with long names.
Closes #7

youtube/templates/settings.html

@@ -4,7 +4,7 @@
 {% block style %}
     .settings-form {
         margin: auto;
-        width: 500px;
+        width: 600px;
         margin-top:10px;
         padding: 10px;
         display: block;