Added downloadmgr.idl.

diff --git a/include/Makefile.in b/include/Makefile.in
index 39a83d7..9e2c934 100644
--- a/include/Makefile.in
+++ b/include/Makefile.in
@@ -14,6 +14,7 @@
 	ddstream.idl \
 	dispex.idl \
 	docobj.idl \
+	downloadmgr.idl \
 	exdisp.idl \
 	mediaobj.idl \
 	mimeinfo.idl \