TCP streaming receiver aborts if too many events received

[driskell]

The TCP streaming receiver in 2.10.0 aborts connections if they send too much data. This is normally part of the courier protocol where a client won't send more than X amount of events without acknowledgement. But with a streaming receiver there is no acknowledgement. So it should ideally handle acknowledgement server-side and simply stop reading whilst there are unacknowledged events.