Automate the build of ja-dic.el.

Automate the build of ja-dic.el.

ja-dic.el no longer needs to be in the repository: it's now
generated as part of the build from bzr.  Also, update SKK-JISYO.L to
match the upstream source exactly.
* .bzrignore: Add leim/ja-dic/.
* leim/ja-dic/ja-dic.el: Remove from repository.  It is still distributed
as part of the Emacs tarball.
* leim/Makefile.in ($(srcdir)/ja-dic/ja-dic.el): New rule.
(compile-main): Depend on it.
* leim/SKK-DIC/README: Update to reflect new build procedure.
* leim/SKK-DIC/SKK-JISYO.L: Update to match source exactly.
This is now the annotated version, to match the upstream file name;
the unannotated one is built from it automatically.
* lisp/international/ja-dic-cnv.el (skkdic-convert): Remove the annotations
from the input, rather than assume that it's been done for us by the
SKK script unannotate.awk.  Switch ja-dic.el to UTF-8.  Don't put
the current date into a ja-dic.el comment, as that complicates
regression testing.

Fixes: debbugs:13984