(U+5E21): Add `<-vulgar' for U+5E32.

(U+5E21): Add `<-vulgar' for U+5E32.
(U+5E32): Add `ideographic-structure'.
(UU+5E42): Unify MJ010875 and HD-KS101990.
(U+5E4E): Add `<-same' for U-00027700, U+5853 and U+5E32; add
`->formed' for MJ010874, U-00027700, U+5853 and U+5E32.
(CU+5E55): Add `<-same' for CU+5E59 and CU+5E54; add `->formed' for
M-27836; add `->interchangeable' for CU+6F20, IU+215B6, CU+83AB,
M-27836, MJ010874, U+5E66 and CU+6F2B; add `->interchangeable@ancient'
for CU+83AB.
(U+5E66): Don't use char-ref for IDC.