Drop code that interacts directly with KMime::Message, and use handy NoteUtils::NoteMessageWrapper instead.
It also allows setting of lastModifiedDate (which will become useful useful as sort role).
Also, drop DocumentCursorPositionRole role for model, which is not used anywhere.
Note that there is large code overlap between NoteCreatorAndSelector and LocalResourceCreator.
Will do something with it in the following patches.