m_ssl_gnutls Create GNUTLS_NEW_CERT_CALLBACK_API and cert_cb_last_param_type
Add the ability to have multiple SSL profiles

SSL profiles are now used instead of fixed SSL settings for everything
SSL, making it possible to use completely different settings for each
listener and outgoing connection.
Split IOHook into IOHook and IOHookProvider

One IOHook instance is created for each hooked socket which contains all
the hook specific data and read/write/close functions, removing the need
for the "issl_session" array in SSL modules.

Instances of the IOHookProvider class are registered in the core and used
to create specialized IOHook classes (OnConnect/OnAccept).

Remove the OnHookIO hook, add a dynamic reference to ListenSocket that
points to the hook provider (if any) to use for incoming connections on
that socket

For outgoing connections modules still have to find the IOHookProvider
they want to use themselves but instead of calling
AddIOHook(hookprov) now they call IOHookProvider::OnConnect().