Sync common modules from Oslo

Sync common modules from Oslo

Identified as dependencies for RPC sync by update.py

Contains code from:
12bcdb7 Remove vim header
e6494c2 Use six.iteritems to make dict work on Python2/3
6d0a6c3 Correct invalid docstrings
fe18bfa Remove keystone from default_log_levels default
0228b81 Logging excepthook: print exception info if debug=True
8b2b0b7 Use hacking import_exceptions for gettextutils._
6d0a6c3 Correct invalid docstrings
fe18bfa Remove keystone from default_log_levels default
13eb01c Adding domain to context and log
27b21bc Unify different names between Python2/3 with six.moves
a6f40ac Don't log to stdout when log_dir is set
4c22556 Use py3kcompat urlutils functions instead of urlparse
0bf03b7 Add network_utils.urlsplit
e456727 Remove useless logging in networks_utils
8b2b0b7 Use hacking import_exceptions for gettextutils._
37e46bb disable SIGHUP restart behavior in foreground
f08f6ba service: replace eventlet event by threading
32cd4c0 Allow configurable ProcessLauncher liveness check
25ff65e Make wait & stop methods work on all threads
7013471 Fix typo in parameter documentation (timeutils)
ae931a9 Avoid TypeError in is_older_than, is_newer_than
ad17a69 Fix filter() usage due to python 3 compability

Oslo version:
7a51572 Merge "Implement cache abstraction layer"
Date:   Wed Jan 15 19:31:16 2014 +0000

Change-Id: If83fb203ecbae912e365118861477a9be834fde3