Created a streamlined loader

Much cleaner and easier to use, and seems to be faster,
but uses memory like it was on sale.
Limit HMDA data loading to 1% of 2010 and 2011
Fix bug with concept mapping
Removed agents from old loader
Fixed memory issues with new loader
Fixed county_taxes definition
Use clojure.core.reducers to speed up map/reduce operations
Upgrade to monger 1.6.0

This allows us to use drop-db
Replaced loader with new loader (loader2)
Fixed test error
Merge pull request #56 from cndreisbach/improved-loading

Faster, better loading