TLS / SSL support

[davidjonas]

Hi!

I needed to get this to work with a https:// server.
I have compiled the socket.io-client-cpp with TLS (OpenSSH) on MacOSX support and replaced the .h and .a files but I got no success.
I still get:

 [connect] Successful connection
 [error] Server handshake response error: websocketpp.processor:20 (Invalid HTTP status.)

I've checked all the forks and no luck...
On the README.md you say you didn't compile TLS because of certificate issues? Could you elaborate on that, please? Maybe it helps me solve the problem and I can contribute.

Cheers and thanks a lot for all the wonderful work.