Removed errant Vagrant config; breaking on modern Vagrant
Add leiningen to the Vagrant provisioning
Fix project.clj to exclude duplicate libraries

Also only compile main.clj when making an uberjar
WIP Add query caching and cache workers

This is still a work-in-progress. It works via REPL, but needs the
front-end built out. Aggregations are now done asynchronously by putting
them as jobs into a Mongo collection. You must start a separate worker
to work the jobs. When the jobs are done, the aggregation is available.