crypto: check protocol version at handshake header

Signed-off-by: Fedor Indutny <fedor@indutny.com>
crypto: fix version check in hello parser

This is a follow up for 89cb740fc31f3be1c3af9fe787c7a405429ccac4
readline: fixes scoping bug

Signed-off-by: Fedor Indutny <fedor@indutny.com>
net: don't throw on net.Server.close()

When close() is called on a non-listening server, a synchronous
error is thrown. This commit causes the error to be passed to
the asynchronous callback function instead.

Signed-off-by: Fedor Indutny <fedor@indutny.com>