Sync with oslo-incubator

Head of oslo-incubator is commit id:
2fd457bf2ccbeb2b84ffb204778b6417cd5405ba

includes a fix for gettextutil.Message handling of deep copy
failures and adding a license header

Change-Id: Ie89de1f95bb6fb9d11058413e682c441c39524f1
Adding network_utils module from oslo-incubator

Needed for fixing bug 1298137

Change-Id: I6803f1af8b0ff036bed634c8aa1cffc52bc508e0
Fix for invalid literal ValueError parsing ipv6 url(s)

Switch to using network_utils for splitting the URL. The code
in oslo-incubator supports ipv6 urls

Change-Id: I76be6173b97eb000319d30b4e9232a5a7c4a5aba
Closes-Bug: #1298137
Merge "Sync with oslo-incubator"
Merge "Adding network_utils module from oslo-incubator"
Merge "Fix for invalid literal ValueError parsing ipv6 url(s)"