Merge pull request #24 from daithiocrualaoich/master

Clean up Sage intern.
Name the VM images in Virtualbox for convenience.
Be sure setup-sage is run once.
Add Bigtop Hadoop2 distribution.
Correct puppet paths to include module names.
Update puppet module dependencies.
Move client sample Vagrantfiles to examples directory.
Use Rake to automatically build the boxes instead of build.sh.
Change to Bigtop Hadoop entirely.
Freshen version numbers, clean lint, add intermediate boxes.
Add dependencies and tests to Rakefile.
Redraft README.md.
Remove intermediate box builds. Means vagrant up still works.
Vagrant is documented in `README.md` instead.
Fix default rake target.
Add a PostgreSQL intern.
Add Bayesian packages to Sage intern.
Add hive to Hadoop intern.
Fix JAGS installation on Sage.
Add standard packages and BUGS to r intern.