* wl-mime.el (wl-define-dummy-functions): New macro.

* wl-mime.el (wl-define-dummy-functions): New macro.
(wl-mime-pgp-decrypt-region-with-epg): Renamed from
`wl-mime-pgp-decrypt-region'.
(wl-mime-pgp-verify-region-with-epg): Renamed from
`wl-mime-pgp-verify-region'.
(wl-mime-pgp-decrypt-region-with-pgg): Renamed from
`wl-mime-pgp-decrypt-region'.
(wl-mime-pgp-verify-region-with-pgg): Renamed from
`wl-mime-pgp-verify-region'.
(wl-mime-pgp-decrypt-region): New function; To select dispatch
function at runtime.
(wl-mime-pgp-verify-region): Ditto.

* wl-vars.el (wl-use-pgp-module): New user option.