- Make the GUI behave better when a disconnect button is pushed.

- Move some of the libnotify logic to guiutil.py and add support for displaying some error messages in a libnotify pop-up.
- Apply some patches provided by sunseraph.  Tweak to the channel regex and checking for a valid AP bssid when monitoring a wireless connection.  Set essid, bssid, and channel in separate calls to iwconfig.
- Add caching for ifconfig and iwconfig results in wnettools.py.  That way we're not needlessly calling the same command a bunch of times in a short period of time (2 seconds).  This removes the need for us to pass around iwconfig/ifconfig output elsewhere, though I've left it in for now.
- Remove unneeded BackendManager instance from networking.py
- Fix last used wired networking autoconnection method

wicd/networking.py

@@ -154,7 +154,6 @@ class Controller(object):
         self.disconnect_script = None
         self.driver = None
         self.iface = None
-        self.backend_manager = BackendManager()
     
     def get_debug(self): return self._debug
     def set_debug(self, value):