If X509_NAME isn't undefined before including x509v3.h, very
weird compilation error occurs. It seems to be caused by duplicate
definitions for this symbols coming from wincrypto.h
Code adapter from RedPeer::ssl_verify_callback() and used by
spice-gtk.
Since v1:
- fixed Makefile.am
- added config.h include
- autoconf alloca added in patch series
- moved int escape inside for loop
- added a failed case when missing assignment
- replaced strlen () by -1
- skip spaces after comma
- c++ guards
I didn't use bool, because openSSL uses int, and it is more future
proof for error reporting.
