Reject the date when the year and/or month is missing

This will set the date to null instead of erroring out when
trying to create the Date object when some of the parameters
are blank.
Yank the magical default for the day attribute
Get rid of some duplication in the date tests
Merge pull request #50 from tevanoff/handle-blank-date-params

Reject the date when any of the date params are missing
releasing 0.2.3, that's one version before 0.2.4.
allow overriding accessors while keeping `super` valid. this happens by creating the delegating accessors in a module which is then included. this allows calling super in users overriding method.
add overriding accessors to README (thanks @cj).
fix typo.
use representable 1.7.5 for inline_representer arguments.
inline forms now use the singularized, camelized property name as their class name. this fixes #47 where I18N used "anon_class" instead of the property name.
if you don't like the name, you can always use ::model to specify your own.
document inline_representer change.
releasing 0.2.4.
add a test to assure #persisted? fails when ::model wasn't called. mention that in the README, as @toxix suggests, and fix #41.
allow proper form inheritance. fixes #53.
adding hooks dependency.
adding CHANGES.