Support connections without file descriptors for EAP-TLS

[rick_dean]

This patch implements SSL connections without a file descriptor
to enable EAP-TLS and similar uses. It contains a monster test
case showing a connection to oneself. The dirty data is communicated
with bio_read() and bio_write() while essential post-connection
parameters can be fetched with master_key(), server_random(),
and client_random().

The patch applies to revision 95 of branch ext-context.

[Jean-Paul Calderone (exarkun)]

Hi Rick,

I'm really excited about this feature. :) I'm traveling at the moment (at PyCon) and won't be back to my usual routine for a couple more weeks, but I'm definitely interested in resolving this ticket.