Added uptime to web controls

Asking for the uptime control will return how long ocarina has been
running.

html/controls.py

@@ -26,6 +26,8 @@ def to_html(wfile, args):
 		ret = next()
 	elif action == "version":
 		ret = ocarina.__vers__
+	elif action == "uptime":
+		ret = ocarina.now() - ocarina.__start__
 	elif action == "title":
 		ret = attrs("title")
 	elif action == "album":