Make Adres value object mutable.

It's hard to use Symfony's form component with immutable objects.
Create Werf value object.
Create Form for Adres value object.
Create form for Werf value object.
Refactor Offerte to use the Werf value object.
Create an event dispatcher for usage in the domain.

The DomainDispatcher implements my own interface and wraps the symfony
event dispatcher. It dispatches events based on the classname of the
event.
Also created an InMemoryDispatcher to ease testing.
Refactor Offerte to use the Werf value object.

Forgot to commit the tests.
Create OfferteOpmaken Interactor.
Use the symfony validator to validate value objects.
Create user GUI for OfferteOpmaken Interactor.
Merge branch 'develop' of github.com:Tactics/Trappenmaker into develop