The ActiveRecord namespace doesn't follow PSR-0 conventions, so Composer's "psr-0" autoloader fails to autoload classes.

Fortunately, loading the `ActiveRecord.php` file loads the common dependencies and registers an autoloader The Old Fashioned Way, and Composer has a config option for that.
Added some newlines for readability.
Implemented 'on' option for validations.
Added tests for on create/update/save
Merge remote-tracking branch 'ethos-development-origin/master' into psr-0-compliant