phpDoc Fixes and Kohana typehint fix

Hey There,

In this PR I hope to have achieved to have corrected almost every phpDoc.

All Cartalyst\Sentry types have been prefixed with a backslash. Such as it now types for \Cartalyst\Sentry\Groups\ProviderInterface not \Cartalyst\Sentry\Cartalyst\Sentry\Groups\ProviderInterface.

Also in this PR is what I believe to be a [bug](https://github.com/Lavoaster/sentry/commit/701523a5fda0952ca216c8219a2e1784359875d7#L8L252) in which you typehint for Validation but since there is no import for it it would infact be typehinting for Cartalyst\Sentry\Groups\Kohana\Validation.