libsaria: Don't immediately enable preference saving

We shouldn't need to save preferences during startup because at this
point only the initial values have been set.  If nothing is changed,
then nothing needs to be saved and we can save some time.  This should
also prevent any problems caused by crashing during a save.

libsaria/__init__.py

@@ -58,6 +58,7 @@ def startup():
 	audio.init()
 	controls.init2()
 	plugin.load_all()
+	prefs.enable_save()
 	event.start("POSTSTART")
 
 

libsaria/trees.py

@@ -224,20 +224,25 @@ class PrefTree(Tree):
 		return val[0]
 
 
+save_prefs_enabled = False
 class PersPrefTree(PrefTree):
 	def __init__(self, file = None):
 		PrefTree.__init__(self)
 		self.file = file
 
+	def enable_save(self):
+		global save_prefs_enabled
+		save_prefs_enabled = True
+
 	def init_pref(self, pref, value):
 		val = PrefTree.init_pref(self, pref, value)
-		if self.file != None:
+		if self.file != None and save_prefs_enabled == True:
 			files.save(self, self.file, ".tree")
 		return val
 
 	def set_pref(self, pref, value):
 		PrefTree.set_pref(self, pref, value)
-		if self.file != None:
+		if self.file != None and save_prefs_enabled == True:
 			files.save(self, self.file, ".tree")
 
 def get_pref_tree(file):