Request for Proton code review: SSL certificate stores (Windows and more)

[Cliff Jansen <cl...@gmail.com>]

Following Andrew's lead, I've posted a pull request for review
feedback on an "extended usage pattern" to the Proton API to specify
alternate certificate containers, for Windows in this case, but it
should also apply to alternate SSL/TLS implementations such as NSS or Java
keystores.

  https://github.com/apache/qpid-proton/pull/2

I expect a wider audience than just "Windows users" may be interested
in the changes in ssl.h and I am especially interested on feedback
there.  Some may prefer an outright API change or addition.

I, of course, also welcome any additional eyes on the Windows-specific
code too.

Cliff