Add unit tests for MessageManagerIterator & fix bug with doctrine context and command optimize method
No sense, the selector takes the messages in error but the command does not handle the messages in error.
Restart_count property can't be null.
Update CHANGELOG.md
Merge pull request #70 from Freckz/TypedNotifications

MessageManagerMessageIterator unit tests & fix optimize on doctrine command
Merge branch 'sonata/master'