Update rootwrap with code from oslo

These are all minor changes bringing nova up to commit c03f247

c03f247 Skip hidden files while traversion rootwrap filters
3f4d1d5 Fix os.getlogin() problem with no tty
fc04531 Send rootwrap exit error message to stderr
3663010 rootwrap: improve Python 3 compatibility
28395d9 Fixes files with wrong bitmode

Fixes bug #1231206

Change-Id: I9f5faefc769fb37d37b6f093fe3a11a6e9f650d4
Merge "Update rootwrap with code from oslo"