Suggest dependencies
Fixes #4460
Fixes #4461
Move Zend\Form from "require" to "suggest"
Merge branch 'master' of github.com:zendframework/zf2 into hotfix/mvc-suggest-dependencies
Move more dependencies from 'require' to 'suggest'
Merge branch 'hotfix/4421'

Close #4421
Merge pull request #4474 from Danizord/hotfix/mvc-suggest-dependencies

Suggest some dependencies in Zend\Mvc
Merge branch 'hotfix/4474' into develop

Forward port #4474