Rework initial auto joining and add big TODOs.

* If we have a configured network, then we always try to connect to it
  as soon as the interface has been brought up.
* If we don't have a configured network and are auto configuring, we
  use the AutoconfigLooper to also do initial auto joins.
* Before issuing auto joins we need to wait for scan results to come
  in, so we watch for corresponding messages.

For now auto joining is a one shot attempt as the infrastructure to
properly tell reasons for scans apart is not yet there.

headers/private/net/NetServer.h

@@ -19,6 +19,7 @@
 #define kMsgRemovePersistentNetwork	'RPnw'
 #define kMsgJoinNetwork				'JNnw'
 #define kMsgLeaveNetwork			'LVnw'
+#define kMsgAutoJoinNetwork			'AJnw'
 
 
 #endif	// _NET_SERVER_H