Fix the loader running out of heap space

I had to eliminate the post-condition for the join-maps function, which
was causing the evaluation to be non-lazy.
Merge pull request #116 from cndreisbach/fix-loader-heap

Fix the loader running out of heap space
Fix issue with errors on CSV throwing a 404
Merge pull request #117 from cndreisbach/csv-404

Fix issue with errors on CSV throwing a 404
Make sure reference columns use compressed names
Merge pull request #118 from cndreisbach/fix-ez-ref

Make sure reference columns use compressed names
Fixed updating in ez-load-ref-column
Merge pull request #119 from cndreisbach/fix-ez-ref

Fixed updating in ez-load-ref-column