Update Phalcon\Mvc\Model return ResultsetInterface (#12574)

* Update Phalcon\Mvc\Model return ResultsetInterface

ResultsetInterface is not imported and causes problems when generating Stubs for IDE. It is generating @return type of Phalcon\Mvc\ResultsetInterface and not Phalcon\Mvc\Model\ResultsetInterface

I think it should be imported in order to easily find correct class

* Update CHANGELOG.md

CHANGELOG.md

@@ -2,6 +2,7 @@
 - Fixed Isnull check is not correct when the model field defaults to an empty string. [#12507](https://github.com/phalcon/cphalcon/issues/12507)
 - Fixed `Phalcon\Forms\Element::label` to accept 0 as label instead of validating it as empty. [#12148](https://github.com/phalcon/cphalcon/issues/12148)
 - Added Aliases for ciphers in `Phalcon\Crypt`
+- Fixed `Phalcon\Mvc\Model` return type ResultsetInterface
 
 # [3.0.3](https://github.com/phalcon/cphalcon/releases/tag/v3.0.3) (2016-12-24)
 - Fixed implementation of Iterator interface in a `Phalcon\Forms\Form` that could cause a run-time warning

phalcon/mvc/model.zep

@@ -34,6 +34,7 @@ use Phalcon\Db\DialectInterface;
 use Phalcon\Mvc\Model\CriteriaInterface;
 use Phalcon\Mvc\Model\TransactionInterface;
 use Phalcon\Mvc\Model\Resultset;
+use Phalcon\Mvc\Model\ResultsetInterface;
 use Phalcon\Mvc\Model\Query;
 use Phalcon\Mvc\Model\Query\Builder;
 use Phalcon\Mvc\Model\Relation;