Module level documentaiton rewrite

//! SMIME implementation using CMS

//!

//! CMS (PKCS#7) is an encyption standard.  It allows signing and ecrypting data using

//! X.509 certificates.  cms is a command implemented in OpenSSL to support a

//! SMIME upgrade to e-mail encryption.  Changes to adding CMS to the SMIME implementation

//! would break SMIME backwards compatbility so the authors of OpenSSL added the CMS

//! keyword.

//!

//!

//! X.509 certificates.  The OpenSSL implementation of CMS is used in email encryption

//! generated from a `Vec` of bytes.  This `Vec` follows the smime protocol standards.

//! Data accepted by this module will be smime type `enveloped-data`.

use ffi;

use foreign_types::{ForeignType, ForeignTypeRef};