Add glyph-images of HNG-KHM.

Add glyph-images of HNG-KHM.
(BUCS+9813): New abstract node.
(U+9813): Add `<-denotational' for BUCS+9813.
(U+987F): Likewise; add `<-simplified@CN' for UU+9813.
(HNG-KHM0149-0): New character; add `<-denotational' for BUCS+9813.
(BUCS+985E): New abstract node.
(U+985E): Add `<-denotational' for BUCS+985E.
(HNG-KHM0580-0): New character; add `<-denotational' for BUCS+985E;
add `<-formed' for U+985E.
(BUCS+9858): New abstract node.
(U+9858): Add `<-denotational' for BUCS+9858.
(U+9858-itaiji-002): Likewise; add HNG-KHM0583-0.