Sync lockutils from oslo-incubator stable/grizzly.

Changes include:

3cb71ff Locking edge case when lock_path does not exist
21925b6 Fix locking issues in Windows
547ab34 Fix Copyright Headers - Rename LLC to Foundation

Fix bug 1158179.

Change-Id: I0d5fb58bef593233068accfcea0dff9fa05f61ef