Replaced PKCS7 methods with CMS ones…

[bm-q]

… to completely support eletronic invoice (OpenSSL 1.0.1c needed)

Also added support to extraction without verification (sometimes even able to extract content from a corrupted envelope)

Reference: https://security.stackexchange.com/questions/41399/openssl-pkcs7-vs-s-mime Reference: https://forum.italia.it/t/problema-decodifica-fattura-elettronica-p7m-di-e-distribuzione/12258