Do not duplicate ReadAsync in DataAvailable.

[madewokherd]

Fixes #164.

[tmds]

Can you change the PR to:

Replace what is in theif (errno == EAGAIN) branch with:

if (!_socket.ReceiveAsync(_waitForData))
{
    DataAvailable(null, null);
}

[madewokherd]

That does seem to work, and it makes sense to me. I'll update the PR.

[tmds]

Thank you, @madewokherd!

[AdrianEggenberger]

Thank you both for finding and fixing this issue. The effects of this issue gave me an uncomfortable feeling in the last weeks as I had no clue where to search for a reason for the missing events. Very glad that it has been found!