(mime-verify-application/pkcs7-signature): New implementation.
* mime-edit.el (mime-edit-sign-smime): New implementation.
(mime-edit-encrypt-smime): Ditto.
* semi-setup.el: Revive setting for application/x-pkcs7-signature.
* smime.el: Removed.
* SEMI-ELS (semi-modules-to-compile): Don't compile smime.el.