[fix] only update changed translations
hook the DatabaseLoader into the Translator service via a compiler pass
Merge pull request #14 from xabbuh/issue-6

hook the DatabaseLoader into the Translator service via a compiler pass
[merge] xabbuh-xml-schema-definition, closes issue #15
test that the translator service definition exists before adding method calls to it
[bugfix] moved to ContainerAwareCommand

fixes error with get() on non-object because container is not yet initialized. Also using ContainerAwareCommand leaves us with less overhead since it already implements Command and ContainerAwareInterface
README update
fix container access
flush the object manager after an entity has been removed
import translations correctly:

 * set the translated message when a translation is inserted for the first time
 * persist the data in the underlying storage layer
minor change: improve manager method usage
remove unused use statement