Docs: Add new deployment and configuration docs

This commit adds:

- index page for deploy docs
- Installing MCollective page
- standard deployment getting started guide
- overview of roles and components
- middleware options index
- minor fixes to the ActiveMQ config reference
- Minor fixes to the server config reference
- client config reference
- plugin deployment guide
- Vagrant demo page

Additionally, it makes the following changes:

- Delete content of EC2 demo page
- Mention using registration as a heartbeat (server config and standard deployment)
- Add deprecation warning and links to the old getting started guides
  (and delete the most outdated one entirely.)