Add mappings for Big5 code points.

Add mappings for Big5 code points.
(U+9638): Apply new conventions for glyph granularity.
(JU+9638): Unify S-8855; add `<-formed' for U+9628.
(U+963D): Unify JC3-68BB.
(U+9641): Unify S-8864; add `<-vulgar' for U+9640.
(U+9658): Unify JC3-68C3.
(U+9661): Unify JC3-68C4.
(U-00028E5F): Unify S-8871; add `<-original' for U+964B.
(U+967C): Apply new conventions for glyph granularity.
(JU+967C): Unify JC3-68C8.
(U+9682): Unify S-8889; add `<-vulgar' for U+9670.
(U+9684): Unify JC3-68CB.
(U+9689): Use `->subsumptive'.
(JU+9689): Unify JC3-68CD.
(U+9694): Use `->denotational' and `->subsumptive'.
(M-41783): Unify JC3-68D0.
(U-00028EF6): Apply new conventions for glyph granularity.
(U+96A4): Unify JC3-68D5.