[xmlsec] xmlSecMSCryptoX509StoreConstructCertsChain

[Aleksey Sanin]

> I'm not sure anymore why Certificate Chain validation functions of MS 
> weren't used. I think there were some issues to get it working properly 
> in this context... but perhaps that was more due to my lack of 
> experience in using these functions. I'm not sure if anyone else tried 
> this as well.
> 

Great! Dmitry, if you can review your patch and make sure that there
are no regressions in the xmlsec unit test then I'll be happy to check
it in :)

Aleksey