ECDSA - GOST support in LibreSSL

[rozhuk . im]

Hi!

I have a working code for DSA - GOST and ECDSA.
Differences between GOST and ECDSA minimal. 
Could you add support GOST LibreSSL. 
I can help as much.

http://netlab.linkpc.net/download/software/SDK/core/include/ecdsa.h