Set python hash seed to 0 in tox.ini

New tox (>=1.7.0) sets a random python hash seed by default. This is
generally good for testing because it will help keep projects working
regardless of the hash seed, but nova unittests don't currently pass
with a random hash seed so set it to the python default seed.

This change will allow us to use new tox again and remove the
restriction on tox<=1.6.1 to run unittests.

Also see Ib54364877a251db48c54dfdc43c503281ea1f04a.

Change-Id: I8834487e8c7bcdbeae8397c1a10a18873976ce61
Partial-Bug: #1348818
Provide docstrings for horizon tables DeleteAction

While it's true that the `horizon.tables.actions.DeleteAction`
code is self explanatory (and hence documentation on its own),
the motivation behind this was to replace """Doc missing.""" with
something more descriptive that will show up at:-
http://docs.openstack.org/developer/horizon/ref/tables.html#horizon.tables.DeleteAction

It would also be good to call `help(DeleteAction)` to get a decent
description of the class.

Change-Id: Ib1198711589ac704278db53d4d53fd655146aaa9
Fix network select widget for launching instances

This fixes the problem where the Networking tab of the Launch
Instance panel does not work if there is more than one network.
Also fixes the similar widget used for firewall rules.

Change-Id: Ied5a800bf8cec7c846c28149d732f769af56f354
Closes-Bug: 1352775
Imported Translations from Transifex

Change-Id: I58035cf8c44636d9a24a93b8d00ca54afc2403e1
Rename add_error methods: Django 1.7 conflict

In Django 1.7, Forms have an add_error() method and our definition
was conflicting with Django's method. Thanks to hertzog@debian.org
for the patch.

Close-bug: #1352919
Change-Id: I1f558cf7f3198a68629738a011e9cae0c3749320
Merge "Fix network select widget for launching instances"
Merge "Provide docstrings for horizon tables DeleteAction"
Merge "Set python hash seed to 0 in tox.ini"
Merge "Imported Translations from Transifex"
Merge "Rename add_error methods: Django 1.7 conflict"