remove duplicate line
require sslStreamBuilder parameter
set socket property on assign, which is required for shutting down the socket.
use the same close logic as in TcpChannel which closes the channel faster.
add test to verify channel closing
set RemoteEndpoint in Assign
call ReadAsync to avoid duplicated code
try catch around reading and writing

which makes the channels more robust against lost connections
Merge pull request #12 from campersau/fix_SecureTcpChannel

Fixes and improvements for SecureTcpChannel