Refactor actions to match Vagrant AWS plugin.

I went through all of the actions and refactored a lot. There are a few
instance actions that do not completely match up. For OpenStack the
concept of 'pausing' and 'unpausing' is storing the machine state in
memory. In later commits I'll add a `vagrant pause` command.

The functionality for the following commands against OpenStack is in
this commit:
     - vagrant destroy
     - vagrant up
     - vagrant suspend
     - vagrant resume
     - vagrant halt