in guess search, trust guess of fields more
better options
Merge branch 'master' into fts
fix ent_seq to make it like JMdict
improved handling of 'frequent'

 - search kanji- and reading-specific frequent tags
 - duplicate frequent columns everywhere - eat even more disk, but save
   up CPU power on JOINs
 - use undocumented spec2 criteria to better match EDICT (P) tag