Don't check as often whether the .redo directory exists.

Just check it once after running a subprocess: that's the only way it ought
to be able to disappear (ie. in a 'make clean' setup).

redo-ifcreate.py

@@ -1,7 +1,7 @@
 #!/usr/bin/python
 import sys, os
 import vars, state
-from helpers import err, mkdirp
+from helpers import err
 
 
 try: