Increasing heap size for both ECHELON and datomic.
wip

* Changes to a registrant to let a registrant entity represent an
individual, a lobbying firm or organization, or an unknown choice
between the previous two options.
* Make it possible to use environ to pass in data location
* Deal with some small edge cases with date parsing
* reformat the structuring code to include more usages.
Merge branch 'master' of github.com:sunlightlabs/echelon