Switch to module-relative import syntax.

Now that the python scripts are all in a "redo" python module, we can
use the "new style" (ahem) package-relative imports.  This appeases
pylint, plus avoids confusion in case more than one package has
similarly-named modules.

redo/jobserver.py

@@ -74,9 +74,9 @@
 # simpler :)
 #
 import sys, os, errno, select, fcntl, signal
-from atoi import atoi
-from helpers import close_on_exec
-import state, env
+from . import state, env
+from .atoi import atoi
+from .helpers import close_on_exec
 
 _toplevel = 0
 _mytokens = 1