Change the default rule name from 'it' to 'all'.

This is a departure from how djb seems to have it set up, but I just like it
better.  It's more like the reasonably-common Makefile standard.  (Although
what make *actually* does is just use the first target declared in the
file.)

redo.py

@@ -11,7 +11,7 @@ v,verbose  print commands as they are run
 o = options.Options('redo', optspec)
 (opt, flags, extra) = o.parse(sys.argv[1:])
 
-targets = extra or ['it']
+targets = extra or ['all']
 
 if opt.debug:
     os.environ['REDO_DEBUG'] = '1'