Merge pull request #2 from allthesignals/develop

Abstract Grouping model created, plus hierarchies
Put profile table into row and col, handle nil muni from index page form
Alter migrations to include relations. Establish relations in models. Test TopicArea's relations.
Make sort_order an integer. Test title, narrative, sort order, and relations
Test all model relations, refactor validations and scope into Grouping, the abstract model
Parameterize the Muncipality name so multiname munis look like 'west-boylston'
Add MOE helper with nil handling, and MOE class
Tiny inline documentation for MOE
Add modals that show muni names for community type and neighbors. Right now, neighbors that display are a random sample and not actually the neighbors. Neighbors to be implemented later.
Add 'support' link. The link to the paypal is a stub.
Add State model, modify support to reflect MAPC's 501(c)3 status
Added Field model, updated Subtopic relation