contribution - pkcs11 smart card support

[ludek.rasek]

Hello,

I have just finished development of PKCS#11 smartcard support into OpenSSH.

It is based on existing approach implemented in sectok and OpenSC support. 
It means it supports private key stored on PKCS#11 device. 

I have developed it on Linux platform and tested on Windows using Cygwin and
after some minor code cealn-up I'm ready to post a patch.

Are you (especially maintaners) interested in such patch? It would be nice if
it become standard part of OpenSSH codebase.

Regards

Ludek Rasek