Added `toxPreGet()' and `toxPostSet()' hooks on retrieving and setting magic properties.
Reorganized interfaces of models and sets.
Added the unit-test for models entities.
Resolved a sequence issue on pre and post setting properties of assemblies.
Rewritten the models entities.
Moved the definition files of exceptions to follow `PSR-0'.
Updated the model entities to keep created ones in memory.
Added the unit-test for models sets.
Rewritten the models sets. (Edit features not implemented.)
Supported sync mode in model entities.
Supported importing for Sets in Model entities.
Merge pull request #82 from marksnoopy/master

Improve `Tox\Application\Input` to support validatings and default values
Added cookie function to response #30.
Added the unit-test for httpsession.
Added session function #31
Added session factory class.
Improved the model entity for operating committable properties immediately.
Implemented modification features for models sets.
Supported sync mode in model sets.
Merged php-tox/tox.