Get a specific listener by id

Merge pull request dddshelf#3 from martinezdelariva/feature-specifica…

…tion

Implementation of Specification pattern.

Fixed a typo on the README.md

Merge pull request dddshelf#4 from oriolgm/master

update serializer version

Persist Events tagged as Publishable

DataTransformer Interface

Remove bindTo on the operation closure...

...it is already bound to the current object context on creation

Improve README description

Domain Event support

Doctrine Published Message Tracker does not run the query to improve …

…flexibility in columns name