Added rendering option to the highstate outputter

- Added an option to the minion config file that allows to return
  information only for those states that changed or failed, skipping all
  successfull states (issue #12648)
fix bugs in highstate whitelist, add tests
Merge pull request #13693 from mgwilliams/highstate-whitelist

fix bugs in highstate whitelist, add tests
Improve initial pillar doc

I think the pillar intro was too light on details. Hopefully this makes
it easier to follow.
Revert _ext_nodes change.
modules.lxc.init(): rename exists=>does_exist to avoid shadowing

************* Module salt.modules.lxc
salt/modules/lxc.py:794: [W0621(redefined-outer-name), init] Redefining name 'exists' from outer scope (line 1469)
Fixed saltnado syspaths var name; CONF_DIR -> CONFIG_DIR

Fixes #13700
remove argument from xdg_config_dir

Closes #13699
Adding test=True ability to schedule module and state.
Make code tiny bit clearer, fix pylint.
Lint fixes.
Formalize a policy for initializing dictionaries.
Merge pull request #13711 from cachedout/dict_policy

Formalize a policy for initializing dictionaries.
Merge pull request #13686 from cro/ext_nodes_fail2

Fix ext_nodes breakage
Merge pull request #13618 from whiteinge/cmd-event-returns

Switch LocalClient().cmd() to watch returns same as Salt's CLI
Merge pull request #13666 from babilen/issues/#13665

Revert "Add master local ip mapping to minion id checking"
Allow traversing dicts nested with lists when matching
fix nodegroup_comp func
Merge pull request #13679 from garethgreenaway/sysmod_work

Adding state docstring to the state_doc function output.
Merge pull request #13685 from bechtoldt/chmod_ssh_known_host

chmod ssh known hosts file in set_ssh_known_host (salt.modules.ssh)