forklift wrapper command

[bastilian]

The idea is to have a forklift command that is a wrapper around vagrant, which can be run from any directory and looks for a boxes.yml (or forklift_boxes.yml) in that directory. Possibly only limited to these boxes.

This would allow to define boxes required for plugin development in plugin directories and manage them from there. The boxes.yml can then also be shared, and plugin authors can include forklift in their repositories (plus the playbooks required to run).

With having now ERB support for YAML files, user specific settings can be put into other places.

Setting up a development environment for a specific plugin is then just a matter of running forklift up and mounting the local clone in the VM.