Fixed the last two bgen-based modules to be buildable on OSX.
diff --git a/Mac/Modules/drag/dragscan.py b/Mac/Modules/drag/dragscan.py
index 833fca1..1d62f6e 100644
--- a/Mac/Modules/drag/dragscan.py
+++ b/Mac/Modules/drag/dragscan.py
@@ -1,7 +1,7 @@
 # Scan <Drag.h>, generating draggen.py.
 import sys
 import os
-from bgenlocations import TOOLBOXDIR, BGENDIR
+from bgenlocations import TOOLBOXDIR, BGENDIR, INCLUDEDIR
 sys.path.append(BGENDIR)
 
 from scantools import Scanner