Check intervals for correct ownership.
Add an attempt at interval creation. Needs more thought.
Remove update and delete methods for accounts.
Introduce a Context struct to permit additional data (like an account) for model methods.
Remove GetDb helper, only used in a couple places.
Rename DbMap to just Db in Context.
Use pointer to account struct.
Go whole hog and use custom request/response structs for JSON handlers!
Remove code for JSON handler wrapper -- now lives in controllers/controller.go.