Multiple fixes and tweaks. #3 #4

re #3 - I want to deploy to be renamed to deployment
re #4 - I want the domain function to be idempotent

* Initial fix to make the domain function idempotent.
* Fixed bug when parsing yaml.
* Fixed bug on linux when relaying on system ssh config.
* Fixed Vhost template not respecting global apache setup (Compatibility with drupal-cookbook).
* Deployment code refactoring.
* Some code clean-up.