New API method for updating request state
Extend add_correspondence API method to optionally accept a state param
Refactor state update API, better error handling

Filters; more 403s, fewer 500s; added logging; less duplication
Sending an invalid state value to add_correspondence now aborts the entire operation
whitespace

includes various code layout fixes
Merge branch 'issues/1418-update-described-state-via-api' into rails-3-develop