[#18] Add folderish content classes and FTI definitions for News Item, Document and Event
[#18] Add helpers to migrate object with changed base class
[#18] Add documentation to migrate all to folderish content type
allow folderish collections
update documentation
[#18] Add folderish content classes and FTI definitions for News Item, Document and Event
[#18] Add helpers to migrate object with changed base class
[#18] Add documentation to migrate all to folderish content type
allow folderish collections
update documentation
Merge branch 'folderish-optional' of git://github.com/plone/plone.app.contenttypes into folderish-optional

Conflicts:
	plone/app/contenttypes/tests/test_migration.py
check of multilingual in form to change base-class
fix displaying the amount of items to be migrated
fix tests
Merge pull request #187 from plone/folderish-optional

Folderish optional