(U+67C1): Add `<-denotational@usage' for A2-DJT-04833 and BUCS+67C1;

(U+67C1): Add `<-denotational@usage' for A2-DJT-04833 and BUCS+67C1;
apply new conventions for glyph granularity.
(U+67C2): Add `<-denotational@usage' for A2-DJT-04834 and BUCS+67C1;
apply new conventions for glyph granularity.
(U-0002B78C): New character.
(U+6A7F): Add `<-denotational@usage' for BUCS+6A7F; apply new
conventions for glyph granularity.
(U+6AAA): Add `<-denotational@usage' for BUCS+6ADF; use
`->denotational' and `->subsumptive'.
(U+6ADB): Add `<-denotational@usage' for BUCS+6ADB; apply new
conventions for glyph granularity.
(BUCS+67C1): New abstract node.
(BUCS+6A7F): New abstract node; unify A2-DJT-05390.
(BUCS+6ADF): New abstract node; unify A2-DJT-05475.
(BUCS+6ADB): New abstract node; unify A2-DJT-05471.
(A2-DJT-04833): New abstract node; use `<-denotational' for BUCS+67C1.
(A2-DJT-04834): New abstract node; use `<-denotational' for BUCS+67C1.