added support for https (using openssl)

[jrialland]

No description provided.

[csachs]

Thanks for the branch! I'm currently quite busy, so some decision will need to be postponed;
generally SSL support is obviously something extremely useful, however since it is security-related, it needs to be done very carefully; and it certainly increases picohttpclient's dependency footprint. My main concern currently would be certificate verification; if done improperly, mitm-attacks might become possible.

[jrialland]

You're welcome :) effectively I have implemented just the bare necessary in order to be able to query the https urls I needed for my own project, it surely cannot be considered production-ready, as you said.

If I ever find the need and the time to add the proper cert validation code, I'll improve on my pull request