Replaced Issue added/updated with Work package added/updated and added a migration for the settings
added copyrights to migration
Replaced Issue with work package in settings for email notifications
added a space
Merge remote-tracking branch 'origin/dev' into fix/issue_in_notifications

Conflicts:
	config/locales/de.yml
	config/locales/en.yml
added a case for notes added in the migration
Merge branch 'fix/issue_in_notifications' of github.com:opf/openproject into fix/issue_in_notifications
Merge pull request #849 from opf/fix/issue_in_notifications