Lots of restructuring, mostly suggested by Bill Bumgarner. Main
externally visible difference is that the factory defaults are
now in a plist file in the bundle, in stead of being hard-coded in
the application.
diff --git a/Mac/OSX/PythonLauncher/PreferencesWindowController.m b/Mac/OSX/PythonLauncher/PreferencesWindowController.m
index 8842162..79344f6 100644
--- a/Mac/OSX/PythonLauncher/PreferencesWindowController.m
+++ b/Mac/OSX/PythonLauncher/PreferencesWindowController.m
@@ -62,7 +62,7 @@
 
 - (IBAction)do_reset:(id)sender
 {
-    [self load_defaults];
+    [settings reset];
     [self update_display];
 }