Fix various pylint issues ( missing import and wrong variable names )

Fix the name of the exported class ( pylint )

fixed indent when looking at delegate_to vars

(We have a jenkins build that creates a [testenv:jenkins] so it needs
there to be a default value

Rename the import, since the directory was renamed for v2

Add missing imports. They are used later in mkdtmp, needed by action plu...

Add/correct missing imports for AnsibleError in v2 lookup plugins

Fix the exception name ( AnsibleParserError, not AnsibleParsingError )

Updated the tox.ini file to run multiple ansible versions.

Add a import for 'builtins' module, used in CleansingNodeVisitor.

This was previously done by ./lib/ansible/utils/__init__.py, but
this code is no longer here in v2 anymore. And since the module
got renamed in python3 to builtins ( https://docs.python.org/3/library/builtins.html ),
we have to use six.

This reverts commit 0345b675.

Purpose: so that devs can use tox to run v1 or v2 of ansible with various versions of python.
For example `tox -e py27-v2 will run python2.7 on v2. Currently, only py26 and py27 are run on v1 when
running just `tox` so that we aren't breaking builds.

Missing import for ansible.errors (pylint)

Do not import all ansible errors and fix the exception raised

Pylint warning, the method _warning is called warning

Pylint show a error "no deprecations variable"

Add another error, who seems to be all over the place

Add back AnsibleFileNotFound ( used in connection plugins )

Improvements to OpenStack inventory script

This reverts the previous commit (d71834d1) and instead fixes the problem
by making sure that options used by ConnectionInformation do not have
defaults set in the playbook objects so they're properly inherited from
the CLI options object if not otherwise specified in the play

Moving this above the play setting means that any default values set
in play (like connection) override any corresponding CLI option, which
is wrong. Generally CLI options should override things set in playbooks