framework: Introduce INetworkManagementService for communicating with netd

This is the framework-exposed interface for the (future) management of
all Android network management functions. Initial support is for providing
tethering.

Updated: Integrate feedback from review; clean up naming

Updated: Switch from add/remove/list to get/set for DNS forwarders
         - allows prioritization / ordering of DNS servers

Updated: Refactor NAT api

Updated: Refactor NAT api (last time sorry)

Signed-off-by: San Mehat <san@google.com>
diff --git a/Android.mk b/Android.mk
index 7c7bb62..d6beac5 100644
--- a/Android.mk
+++ b/Android.mk
@@ -111,6 +111,7 @@
 	core/java/android/os/ICheckinService.aidl \
 	core/java/android/os/IMessenger.aidl \
 	core/java/android/os/IMountService.aidl \
+	core/java/android/os/INetworkManagementService.aidl \
 	core/java/android/os/INetStatService.aidl \
 	core/java/android/os/IParentalControlCallback.aidl \
 	core/java/android/os/IPermissionController.aidl \