Improve installation portion of Vagrantfile
Improve installation portion of Vagrantfile

* Consistently use the install_package function
* Avoid installation of java 8 if already installed
* Add pseudo-code for optimizing all package_install invocations in the case of a package already being installed.
* Group together all java-related installation/setup steps
* Use the PREFIX variable consistently for output logs

DarinJ/storm,DarinJ/storm,erikdw/storm-mesos,erikdw/storm-mesos,changreytang/storm-mesos,mesos/storm,erikdw/storm-mesos,mesos/storm,DarinJ/storm,changreytang/storm-mesos,mesos/storm,changreytang/storm-mesos