Added ExitKernel16 (replacing USER_ExitWindows), ExitProcess16, and
MapProcessHandle; stub for BUNNY_351.

diff --git a/loader/task.c b/loader/task.c
index 05052e2..520bf48 100644
--- a/loader/task.c
+++ b/loader/task.c
@@ -583,8 +583,7 @@
     if (nTaskCount <= 1)
     {
         TRACE_(task)("this is the last task, exiting\n" );
-        SERVICE_Exit();
-        USER_ExitWindows();
+        ExitKernel16();
     }
 
     /* FIXME: Hack! Send a message to the initial task so that