Prior to this commit, there was no way to add additional ssh arguments
within a Vagrantfile for a given vagrant machine. This commit introduces
a new option extra_args that allows users to pass in a single argument
or an array of flags that will be added onto the ssh command.
This commit allows the user to configure two additional options that
were previously not configurable: Compression and DSAAuthentication.
Each config option is set as a boolean, and if left out of the config
will default to its previous behavior which is included and set to
"yes". If the user explicitly sets it to false, it will not be included
as an ssh option.
This adds two new SSH configuration options:
- `keys_only`
- `paranoid`
These values were previously hard-coded, but can now be user-specified.
Fixes GH-4275
Brian Cain
Seth Vargo
Mitchell Hashimoto