API extention needed for findAll

[RickRainerLudwig]

In a project of mine I have some root nodes of trees in my graph db. These root nodes need to be found and read all to provide a selection. For that purpose a findAll() method is needed in API to retrieve all nodes of a certain type.

[CrystalMethod]

We've started to talk about repository/service calls like findAll() - see #105. I think we should not continue adding more find/create/.. to the XOManager implementation.

[RickRainerLudwig]

I definitely need something lightweight to get all nodes of a certain type.

Maybe this could be done by using something like xoManager.find(Type.class, null),but a null in any API is ugly...