* Added support for asking if a given node type can have children or grandchildren and what types of nodes can be it's parent or child
* Removed canHaveChildren methods from leaf and branch nodes and converted use of them to depend on factory to read static rules from constructor lookup by type
Change-Id: I9769f95647066576416bacb791c4b68dd0285b35
Within ve.dm.DocumentFragment it makes more sense to call the root node (which is always a document node) a document node, especially since there may be a different node used as a root.
This commit also adds test for getDocumentNode and getNodeFromOffset which uses the offset map.
Change-Id: Ic4609233cedc41f7e5a5f8fdb0e6178652c95554
And fixed ve.dm.DocumentFragment constructor to generate a correct offset map which creates references to branch nodes only
Change-Id: If9e515be0c63d272bfed9bf4da625a48edd36f48
