Merge branch 'hotfix/#6512-fix-#6511-sharedeventmanager-return-values-phpdoc'

Close #6512
Close #6511
Fixes #6506 - as of zendframework/zf2@eaa78740c352cdaf0f44179204674b56b7f19ad6, `zendframework/zend-form` is required in the MVC
Merge branch 'hotfix/#6506-missing-zend-form-dependency-in-zend-mvc' into develop

Forward port #6506