- dispatcher tests: register the server before the client connects
(Connect race), poll the Connected ack non-blocking with a deadline,
keep the client socket non-blocking so a full buffer yields EAGAIN
instead of a blocking send() past any deadline
- piethernet test: use a TCP client against a never-reading listener
(server-object writeDevice is a no-op) and 32 MB to exceed the
~10 MB loopback buffers
With piethernet/pistreampacker reverted to master all four tests
fail (8 ms .. 40 s); with the fixes ctest is 342/342.