Updated listener addition in doWithApplicationContext

Now we use I18nFieldsPersistenceEventListener
Fix MissingMethodException in I18nFieldsHelper

Error evaluating expression [alertInstance?.title_en_US] on line [10]:
groovy.lang.MissingMethodException: No signature of method:
groovy.util.ConfigObject.contains() is applicable for argument types:
(java.lang.String) values: [en_US]
Merge branch 'redis_integration' of https://github.com/aberbenni/grails-i18n-fields-plugin into redis_integration
Removed useless configuration from plugin
Fixed some errors on pull request
Fixed problems when a domain class has no i18nFieldsRename
Better and simplified I18nFieldsPersistenceEventListener
Support for delete a entity
Merge branch 'inmediate-bugfixes' into redis_integration