Add minimal support for ipmitool

Adding just a couple of ipmi commands that ipmitool always calls.
I'm doing this because in order to run the ipmitool lan 1 <parms>
instead of just the raw command the get channel info was needed.
diff --git a/Makefile b/Makefile
index 58e7310..7a3b6af 100644
--- a/Makefile
+++ b/Makefile
@@ -15,7 +15,8 @@
               ipmisensor.o     \
               storageaddsel.o  \
               transporthandler.o  \
-              globalhandler.o  
+              globalhandler.o  \
+              groupext.o
 
 LIB_HOST_SRV_OBJ = host-services.o