||the base interface for nodes that were versioned and turned either into
InternalFrozenNode or InteralFrozenVersionHistory.
||The InternalFrozenNode interface represents the frozen node that was generated
||This interface defines a frozen versionable child node, that was created
Node.checkin() with a OPV==Version node.
||This interface defines the internal version.
||This interface defines the internal version history.
||This interface defines the base for all internal versioning items.
||This interface defines the version manager.
||This Interface defines the version selector that needs to provide a version,
given some hints and a version history. the selector is used in the various
restore methods in order to select the correct version of previously versioned
OPV=Version children upon restore.