(U-00020087): Add `<-vulgar' for U+4DB9.

(U-00020087): Add `<-vulgar' for U+4DB9.
(U-0002CF09): New character.
(U+4E51-itaiji-001): New character; use `<-denotational' for U+4E51.
(BC-887C): New character; use `<-denotational' for U-0002CF09.
(U+4E56): Apply new conventions for glyph granularity.
(IU+200B9): Add `ideographic-structure'.
(U+200B9-itaiji-004): New character; use `<-denotational' for
U-000200B9.
(A-BC-85A8): Use "&U-i001+2FF1;(U+2FF1-itaiji-001)千x" instead of "⿻千x".
(BC-85A8): Ditto.
(U-000200BF): Add `<-denotational@component' for A-IWDSU+200BF; apply
new conventions for glyph granularity.
(U-0002CF15): New character.
(A-IWDSU+200BF): New abstract node.
(A2-DJT-00100): Unify BUCS+4E56.