Fix BC break with skeleton for Translator Service

[weierophinney]

• Mvc\TranslatorServiceFactory was missing the "implements FactoryInterface" declaration, making it fail as a valid factory.
• Just fixing the factory did not work, however, as a circular dependency was occurring, as changes in TranslatorServiceFactory meant it was looking for existence of an alias already defined in the skeleton, and pointing back at the same service.

What I did was:

• Add a check for a Zend\I18n\Translator\TranslatorInterface service in the factory; if it exists, it is pulled and pushed into a Zend\Mvc\I18n\Translator instance, and that instance is returned.
• If a translator key is present in configuration, and non-empty, that is passed to Zend\I18n\Translator\Translator::factory, and the result passed to a Zend\Mvc\I18n\Translator instance, which is returned.
• Finally, if none of the above are true, a DummyTranslator instance is created, passed to a Zend\Mvc\I18n\Translator instance, and that instance is returned.

This addresses all BC breaks with the existing skeleton.

Fixes #5684 .

[weierophinney]

Okay, ready to merge now!

[coolmic]

I preferred the behavious of DASPRID PR ( #5406 )

Before his PR :

I have like 10+ modules, with translation files for each one.

array(
    'translator' => array(
        'translation_file_patterns' => array(
            array(
                'text_domain' => 'ice-admin-auth',
                'type' => 'phparray',
                'base_dir' => dirname(__DIR__) . '/i18n',
                'pattern' => '%s.php'
            )
        )
    )
)

Translation files were loaded even if I didn't use translator.

With his PR :

None of my translation files are loaded if I didn't define 'translator' in the service manager.

Now with this PR, all my translation file are loaded, or I have to remove 'translator' entry in each module config.

[prendit]

The new Zend\Mvc\I18n\Translator (MvcTranslator) is lacking some public methods of the old Zend\I18n\Translator\Translator which it previously extended. The MvcTranslator also does not allow access to the protected $translator which makes it impossible now to change the locale on the fly for example.

Will the MvcTranslator be extended before 2.3 goes to master, or we have to extend it in the future, so we can use those public functions?

[aimfeld]

I had to account for this minor BC break in my custom Translator extension when updating from ZF 2.2.5 to 2.3.0. I now extend my custom Translator from Zend\I18n\Translator\Translator instead of Zend\Mvc\I18n\Translator and implement Zend\Validator\Translator\TranslatorInterface
The following worked for me:

namespace MyLib\I18n\Translator;

use Zend\Validator\Translator\TranslatorInterface as ValidatorTranslatorInterface;

class Translator extends \Zend\I18n\Translator\Translator implements ValidatorTranslatorInterface
{
    // ...
}