Important RFC for Addon authors

[Fedor Indutny]

Hello people!

Please feel free to ignore this if you don't write/maintain C++ addons for node.

With this PR:

https://github.com/joyent/node/pull/8355#issuecomment-55395952

I'm going to export some External-wrapped pointers to structs like SSL, SSL_CTX to make it possible to write some extensions for a core modules.

What I am trying to figure out right now - is what another pointers do you want to be exported?

Cheers,

Fedor.