Sync oslo lockutils to nova

There is some update for lockutils in oslo, sync from oslo

The commit to be merged:
edd73c9 Merge "Improve help strings"
e446fe5 Merge "Fixed several typos"
fe3389e Improve help strings
f3f14c9 Fixed several typos
0f495ee Emit a log statement when releasing internal lock
f0dd798 Remove rendundant parentheses of cfg help strings
006d9a2 Allow external locks to work with threads
9b73c19 Re-enable file-based locking behavior
edce46c Use Posix IPC in lockutils
ac84a40 Update log translation domains
ee4df7f Merge "Add remove external lock files API in lockutils"
fcf517d Update oslo log messages with translation domains
37a1de8 Move the released file lock to the successful path
3c125e6 Merge "Use threading.ThreadError instead of reraising IOError"
de826f2 Merge "Have the interprocess lock follow lock conventions"
b0d0c33 Add remove external lock files API in lockutils
e71cd1a Merge "Trivial: Make vertical white space after license header consistent"
4f6190a Use threading.ThreadError instead of reraising IOError
195f0b1 Have the interprocess lock follow lock conventions
15cca4b lockutils: move directory creation in lock class
81fe39e lockutils: remove lock_path parameter
14d3669 lockutils: expand add_prefix
dc06d55 lockutils: do not grab the lock in creators
a0948cb lockutils: remove local usage
df8e051 lockutils: split code handling internal/external lock
8b2b0b7 Use hacking import_exceptions for gettextutils._
6d0a6c3 Correct invalid docstrings
6fa29ae Trivial: Make vertical white space after license header consistent
12bcdb7 Remove vim header
79e6bc6 fix lockutils.lock() to make it thread-safe
ace5120 Add main() to lockutils that creates temp dir for locks

Related-bug: #1256306

Change-Id: Iced751f059bd9a893ccefb5f98d63df29f40c622
Merge "Sync oslo lockutils to nova"