Consolidate xresolv functions
There are a number of places in the jmdictdb code where Xrslv (unresolved xref) need to be resolved to real Xrefs by finding a unique entry with matching reading and kanji. But the code to do this has been independently reimplemented in multiple places in the code: * xresolv.py * jdb.py (resolv_xref() function) * jelparse (resolv_xrefs() function) * tests_edconf_realign.py We really should unify all these if possible.
[Imported from JMdictDB Issues Tracker: IS-218/msg541]