switching to puppies and kittens for config

[sirkitree]

see: https://www.reddit.com/r/backdrop/comments/2tfnod/best_practices_for_config_management/coagcox

This switches us to use a simpler configuration setup.

The only thing that is needed to set this up is to have your local settings.php point to the correct directories.

todo:

• [x] document in readme
• [x] update default.settings.php with the default settings local should have
• [ ] change prod's settings.php to the following once this is merged

$config_directories['active'] = '/var/www/vr.lulladev.com/config/puppies';
$config_directories['staging'] = '/var/www/vr.lulladev.com/config/kittens';

[sirkitree]

@davexoxide and @wesruv - please review this when you have a chance. I think it's much easier to understand this way and it's what was recommended by Jen here: https://www.reddit.com/r/backdrop/comments/2tfnod/best_practices_for_config_management/coagcox

This is essentially the "Figure-8 approach" described here: https://github.com/backdrop/backdrop-issues/issues/855#issuecomment-91419775

I'm going to merge this now and test it on the dev server, but please take the time to review this approach to understand it.