Update Vagrantfile for Salt deployment

* Add salt provider
* Track develop branch of salt for bootstrap. This addresses an issue with
  postgres_user present in 0.17. Pinning the next stable release should be
  adequate
* Bump up memory
* Change web port to match nginx config
* Add better dns resolver, maybe not required
Migrate Chef config to Salt, improve site deploy

* Migrated most services 1-to-1
* Updated package install to work with pip 1.5+
* Updated application setup to perform actions on database as well
* Added temporary local_settings to get the server running
Add hiredis requirement
Tighten exception catch on settings
Update local_settings for vagrant
Fix redis settings on onebox
Change checkout to use vagrant share, add auth fixture

* Adds auth fixture for adding user docs/docs, automating adding a user so
  loading test data can be automated
* Adds a vagrant share to the checkout path, so local changes are now live in
  the vagrant box
* Updates salt deploy for both
Add singlehtml builder option.
Add localmedia builder, and use it for zipped html.
Move zip html logic into single local media builder.
Be defensive with JSON parsing
It's already an object.
Show exception
Update webhooks.rst

Updated github procedure to current interface.
Merge pull request #680 from tiagopereira/patch-1

Update webhooks.rst
remove unused import
Fix up singlehtml builds
A bit more safety checking
Typo in alternate domains docs.

Its not it's :)
Merge pull request #686 from tomdyson/patch-1

Typo in alternate domains docs.