[MB-11203] SSL-enabled memcached will hang...

A large pipeline input lead to memcached effectively
performing a under-read of the input buffer.  This occured
when memcached moved to conn_waiting as part of yield, we
only check rbuf for data when a SSL_peek is needed for SSL
connections.

Also on the drain_recv code we could get into a situation
where we'd read everything off the network but didn't quite
handle the SSL_read -1 error correctly. Again we could end up
yielding and never wake up again because there's no more data
on the network, yet there's data in our intermediate ssl read
buffer.

testapp changes are required because this defect occured when
a large single sendto occurs.  The old SSL code in testapp
used openssl methods to send/recv, which actually chunked up
large pipelines using smaller writes, hiding the bug because
we kept stimulating memcached.

New code allows testapp to take full control of sends using
whatever chunking scheme we wish.

Also removed some time tests which weren't needed and were
causing some occasional failures because they were a little
intolerant.

Change-Id: Ie2a3374fc32ad57a122040ad359e3148d6bdeffd
Reviewed-on: http://review.couchbase.org/40417
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>