Implemented get-doit and switched exception handling to slingshot
Upgraded to Clojure 1.6.0
Refactored id & doit validation into closure functions
Re-worked validation function, and corresponding data functions & tests to a more flexible validation mechanism
Added attribution comment
Replaced validation type IDs with camel-case type IDs to signify type checks
Add new tests for get & delete, refined validation functions (removed macro)
Added messages to validation exceptions
Some name changes, namespaced data types