add Japanese translation
load metadata event listener
Merge pull request #47 from 77web/translation-ja

add Japanese translation
Merge pull request #48 from molchanoviv/master

load metadata event listener
Little clean up and fix empty array bug
Check if model class is defined
added check for sylius.config.classes parameter existence
Merge pull request #49 from molchanoviv/master

added check for sylius.config.classes parameter existence