Add ability to turn BT on / off on a per application basis.

This changes adds an API for system applications
to enable bluetooth without all the side effects like
auto connection to headsets etc.

Also some tweaks to the adapter state machine

Change-Id: Ib9f22d548a26d72334b300101c8eb0d80f08a4bb
diff --git a/Android.mk b/Android.mk
index 7b8d0bc..737202d 100644
--- a/Android.mk
+++ b/Android.mk
@@ -93,6 +93,7 @@
 	core/java/android/bluetooth/IBluetoothHeadset.aidl \
 	core/java/android/bluetooth/IBluetoothHealthCallback.aidl \
 	core/java/android/bluetooth/IBluetoothPbap.aidl \
+	core/java/android/bluetooth/IBluetoothStateChangeCallback.aidl \
 	core/java/android/content/IClipboard.aidl \
 	core/java/android/content/IContentService.aidl \
 	core/java/android/content/IIntentReceiver.aidl \