Log Message:
Update to 2.3.1, provided by Hiramatsu Yoshifumi in PR 28434:
Changes:

* lisp/tc-mazegaki.el: C-g can interrupt kana-kanji conversion.

* lisp/tc-is18.el:
* lisp/tc-is19.el:
* lisp/tc-is20.el: fix infinite loop bug.

* lisp/tutc-tbl.el: fix translation table.

* lisp/eelll.el: use colored background in bitmap display mode.

* skkinput3/Makefile.am: merged patches/patch-ab