libsaria: New preferences functions

The new preferences code is much easier to work with.  Rather than
inheriting from a complicated tree class, I just set values in a python
dictionary directly.

libsaria/prefs.py

@@ -2,5 +2,27 @@
 
 import storage
 
-prefs = storage.load_file("preferences", dict)
+FILE  = "preferences"
+prefs = storage.load_obj(FILE, dict)
+save_enable = False
 
+def save():
+	if save_enable == True:
+		storage.save_obj(FILE, prefs)
+
+def enable_save():
+	global save_enable
+	save_enable = True
+	save()
+
+def get(key):
+	return prefs.get(key, None)
+
+def set(key, value):
+	prefs[key] = value
+	save()
+
+def init(key, value):
+	val = prefs.setdefault(key, value)
+	save()
+	return val