Support seq/coprpus in unresolved xrefs (Xrslv objects)
Currently the <xref> elements in the jmdict-ex.xml DTD allow for including seq number and corpus information (via attributes) in addition to the kanji, reading, and sense info in the xref element value. However, if the xref is not imediately resolved to an Xref upon reading, there is no way to preserve this information in an Xrslv object. Also consider: xref order is lost if some xrefs are in the Entr's _xref list and some in its _xrslv list. Perhaps we should have single _xref list containing both Xref and Xrslv objects?
[Imported from JMdictDB Issues Tracker: IS-150/msg353]