Add prefs2 variable / remove vars

The prefs2 structure is where I will store my new tree-based
preferences.  I'll use this for now until everything gets moved over.  I
also remove the vars variable since nothing uses it.

libsaria/__init__.py

@@ -12,13 +12,13 @@ if __dev__ == True:
 
 import event
 import path
+from trees import Tree, PersPrefTree
 from map import Map
 from cache import Cache
 
-# Variables are not saved across sessions, but preferences are
 # The cache is also saved across sessions
-vars  = None
 prefs = None
+prefs2 = None
 cache = Cache()
 
 plugin = None
@@ -28,13 +28,13 @@ lastfm = None
 
 # Initialize helpful variables
 def init():
-	global vars
 	global prefs
+	global prefs2
 	global audio
 	global lastfm
 
-	vars = Map()
 	prefs = Map("preferences")
+	prefs2 = PersPrefTree("preferences")
 	import audio
 	import lastfm
 
@@ -47,11 +47,6 @@ def init_pref(key, value):
 	if prefs.get(key, None) == None:
 		prefs[key] = value
 
-def init_var(key, value):
-	global vars
-	if vars.get(key, None) == None:
-		vars[key] = value
-
 
 def startup():
 	global plugin