This commit updates links affected by doc migration.
Note that other links are not touched in this commit.
Fixing other broken links or changing http to https
should be covered by a separate patch.

Also convert http links to docs.openstack.org to https per reviewer
request (though it is not directly related to doc-migration).

Note that this commit does not touch files under releasenotes/notes/.
If we touch release notes in older releases, reno will considers
it as a release note in the current release.
(Pike release notes are clean up in a separate patch.)

Change-Id: Iba9bd465ef08014a4972584cf4da6e7d77961119

The best practice in Python is not to use mutable object (i.e. list,
dictionary, or instances of most classes) as value of default
argument (see https://goo.gl/Kwhg0T). A hacking rule to enforce this 
practice is added as well.

The patch was inspired by CR https://review.openstack.org/#/c/198465/ 
and took most of its code from it as well. That's why original 
copyrights are kept.

Closes-Bug: #1471349
Change-Id: Ia77b1736dbc3d4e28ff2d2c3424e9cfcaefa5077

We have one more import with #noqa: django.conf.urls.include that is also
commonly used in urls.py module and could be included to the list of
import exceptions. This change has also revealed one unused import.

Change-Id: I47cc582340625aac87ab0242b147e11ef1d9b38e

We have two imports with #noqa: django.conf.urls.patterns and
django.conf.urls.url however using them is a standard way of creating
any urls.py module. So there are over 150 imports in Horizon code
where #noqa could be replaced with two lines in list of import_exceptions.

Change-Id: I81c3290e0dc958b5037dd6a87e44df18adfbe751

Since there is a couple of new import exceptions in tox.ini,
we should add corresponding lines to HACKING.rst list.

Change-Id: Ia45eb9a5dcdc4db5205f235c85cfeab80c62d786

Django changed the name to force_unicode and it's only available in
python2 as an alias of force_text. The new name is available since
Django 1.4.2

Closes-Bug: #1345642
Change-Id: Ida8c545ceec7c31999f2497d540a0dc5a653d286

We have a lot of import with #noqa that is there to ignore h302,
because it's traditional to import and use a name directly, instead
of a whole module. This hides other errors and gives people the
impression that it's actually fine to import non-modules, you just
have to slap #noqa on those lines.

I went through the code and identified about a dozen names that are
most commonly imported this way. I remove the #noqa tag from them,
and added them to the list in import_exceptions.

I also removed a few unused imports that were revealed in the process.

Change-Id: I27afb8e2b1d4759ec974ded9464d8f010312ee78

Add a point to HACKING.rst pointing to the Horizon docs about
contributing.

Add information about JavaScript support policy to the contributing
docs.

The policy is based on:
http://lists.openstack.org/pipermail/openstack-dev/2013-November/020342.html

Change-Id: I16a51c7ab7faf68d6e7984c113da175c5c08650d

Make HACKING.rst have the same format as in other OpenStack repos. When
working across multiple projects its nicer to have files have the same
formatting to reduce confusion.

Change-Id: I078f7ba512cfd8ccaf646e37287bcdbb11e54e90

The current links in the HACKING file are broken. This references the
correct location for contributors to view.

Change-Id: I785ae8e01a7e88f7bc3b94c59ea0c35068fede13

Add HACKING.rst but instead of copying the file around point to the new
cannonical location for it
https://github.com/openstack-dev/hacking/blob/master/HACKING.rst

Also expand out the flake8 H series ignores, so they can be enabled one
by one.

Change-Id: I6ec39d00c3beabbc3e661754bac6e43a0fb351d6