Added Gemfile to help make testing, etc. easier for contribs.
Added first bits of migrations support.
Merge branch 'master' of https://github.com/sxross/MotionModel

Conflicts:
	Rakefile
bumped version to 0.5.0.pre1
Changed hook methods to pass a "sender" object, which is the object that
either is about to change or has changed. This may break existing code.
Modified spec to recognize sender argument for hook methods.
Added hook documentation, modified CHANGELOG and README to reflect new hook behavior.
Fixed readme so sample classes (e.g. Tasks) compile by adding include MotionModel::ArrayModelAdapter to their definition
Merge pull request #31 from spnkr/master

Fixed sample code in readme so it compiles
Stub validation hooks
Pass column vs. column_name where possible. Disabigulate by using column_name where appropriate
Made #column_named public to allow reference across associations.
Stub :destroy hooks
Extract and delegate dynamically-defined methods into instance methods. This should be more efficient and should improve backtrace visibility.
Column options pulled out into readers to make references more succinct. Also delegating some methods.
Polymorphic helper methods
Remove the #{attr}_relation requirement for ArrayModelAdapter
Declare ID column when inherited, not when other columns are declared
Rename #column_named to #column and make public for easier debug. Call from many methods which can now accept either the column instance or its name.
Relation handling fixes to prepare for SQL, including some method renaming
Make #inspect to default to more succinct output. Lots of attributes can clog up display during spec failures.