Revert "Use a specific version of AUCTeX."

This reverts commit f48e380bb3e8deef4f5e2b6e9b88af28d6741f56.
Add the path to the ddskk directory to load-path.
Put a large SKK dictionary.
Install 'ddskk' into ./site-lisp.
Add 'skk-autoloads.el' generated by make.