(A-IWDSU+5A1B): New abstract node.

(A-IWDSU+5A1B): New abstract node.
(A-J0-3864): Add `<-denotational' for A-IWDSU+5A1B; unify A-JU+5A2F;
add `ideographic-structure'.
(U+5A1B): Add `<-denotational@usage' for BUCS+5A1B; apply new
conventions for glyph granularity.
(U-0002F863): Use U+5A1B instead of A-J0-3864 as its mother.
(U+5A31): Use `->denotational' and `->subsumptive'; add
`<-denotational' for A-IWDSU+5A1B; add `<-denotational@usage' for
BUCS+5A1B.
(U+5A2F): Add `<-denotational@usage' for BUCS+5A1B.
(BUCS+5A1B): New abstract node; unify A2-DJT-02118.