Comment 2 for bug 475501

No problem. I'm going to propose a merge after adding some checks.

I've got no experience in python windows programming but as far as I know functions like os.umask() should work in a compatible workaround way or be ignored on windows.

so far the patch has this functions:
 - bzr's ~/.bazaar/authentication.conf is initially created with permissions 600
 - bzr emits a warning upon accessing the file if it's permissions are insecure (g!=0, o!= 0)
 - warning can be disabled in ~/.bazaar/bazaar.conf