OVS Agent: limit veth names to 15 chars

The maximum length of a veth interface name is 15 characters.
This patch limits the length of the veth names created for
integration bridges by switching to a fixed-length hashing
mechanism if the normal name would exceed the allowed length.

Closes-Bug: #1328288
Change-Id: I432cee62a6dc91f268becbc91f8024c23dd0bfac
Use import from six.moves to import the queue module

The name of the synchronized queue class is queue instead of
Queue in Python3.

Change-Id: I5c5aba89b30b311bbfba2b64c61ea566d339b7c9
Closes-Bug: #1327975
extensions: remove 'check_env' method

The method is not documented or used.
It was introduced for quota but unused since commit 603e3b78.

Closes-Bug: #1328362
Change-Id: Id0a4d8606f34e54468ed0de26adbf25ff273079e
Imported Translations from Transifex

Change-Id: Ib6b1eb8816862ba17c40d7fb0a510e1936503ec4
multiprovidernet: fix a comment

Change-Id: I8a09af9f77bb589203bb47fcc1c6c7b704a5b6c2
Merge "Use import from six.moves to import the queue module"
Merge "Imported Translations from Transifex"
Merge "extensions: remove 'check_env' method"
Merge "OVS Agent: limit veth names to 15 chars"
Merge "multiprovidernet: fix a comment"