Caching feature

Please, use readme, for details about caching feature implementation.

Release v0.0.3

Fixed availability gem provided rake task in the host rails application.

Version v0.0.2

This release carriers the next changes:

1. Fixed with table naming
2. Refactored internal parts
3. Implemented settings register. Now you may to get settings list by Settingify.registered_settings.
4. Added rake task for syncing defined settings in initializer to DB.