RAVE-1099 | Introduces Vagrant.

JIRA: https://issues.apache.org/jira/browse/RAVE-1099

This PR introduces vagrant so we don't need to install dependencies on our local machine; now, everything is sandboxed. The vagrant box will use the maven 3.3.1, tomcat7, and oracle's java7 packages. @jmeas and I replaced the information in the `readme.txt` to accurately portray how to start up the vagrant box.

Let me know if this is the appropriate forum for submitting a PR or if we need to send our PR (and how) to the mailing lists.
You might wonder if our `creates` flag in the maven task to install the deps still works, since we just test for `{{ maven_rave_dir}}/target`. It does still work as a `/target` directory is created in the root project directory.