Start window manager refactoring.

Move all of the pieces into a new com.android.server.wm package.

Change-Id: I942b7bcfb84ee0f843f47d58e55ffc5a93c0da94
diff --git a/services/java/com/android/server/am/ActivityManagerService.java b/services/java/com/android/server/am/ActivityManagerService.java
index f3ccd38..399c19a 100644
--- a/services/java/com/android/server/am/ActivityManagerService.java
+++ b/services/java/com/android/server/am/ActivityManagerService.java
@@ -24,8 +24,8 @@
 import com.android.server.ProcessStats;
 import com.android.server.SystemServer;
 import com.android.server.Watchdog;
-import com.android.server.WindowManagerService;
 import com.android.server.am.ActivityStack.ActivityState;
+import com.android.server.wm.WindowManagerService;
 
 import dalvik.system.Zygote;