This method notifies of the start of an entity. The DTD has the
pseudo-name of "[dtd]" parameter entity names start with '%'; and
general entities are just specified by their name.
name The name of the entity.
identifier The resource identifier.
encoding The auto-detected IANA encoding name of the entity
stream. This value will be null in those situations
where the entity encoding is not auto-detected (e.g.
internal entities or a document entity that is
parsed from a java.io.Reader).
augs Additional information that may include infoset augmentations
XNIException Thrown by handler to signal an error.