[Vanilla] Vanilla plugin extension to install Hadoop clusters from scratch

Currently Vanilla Plugin uses cloud images with pre-installed Java and Hadoop packages.
These images can be built using diskimage-builder instructions:
https://github.com/stackforge/savanna-extra

This blueprint aims to implement Hadoop clusters deployment on the empty cloud images.
It can be implemented as extension of current Vanilla plugin:
https://blueprints.launchpad.net/savanna/+spec/vanilla-hadoop-plugin

This extension has to have:
- Downloading all need packages to run Hadoop services;
- Configuring OS specific things as well as Hadoop services;