test_connect_eintr3.py: even better:

- block signals in the server thread
- count signals during connect()
- display progress: "*" for signal received during connect(), "_" for signal received before/after connect(), "[" and "]" for the beginning and end of a connection, "#" for client connection reset

Example of output on FreeBSD:

Register SIGINT
Register SIGALRM
Register SIGWINCH
Register SIGTERM
Register SIGCHLD
Send SIGALRM every 200.0 ms
Run func() during 5.0 seconds
Type CTRL+c, resize the window, etc.

___[]______[]_____[_*#]_____[#]__[#]________[#]____[#]_____[**]____[*#]______[__#]___[#]_____[#]____[*#]______[#]______[#]_____[*#]_____[#]_____[#]______[#]______[#]______[#]______[#]______[#]____[#]_______[#]_____[#]_______[#]_____[#]_____[#]______[#]_______[#]____[#]______[#]______[*#]_____[#]________[#]__

Test completed in 5.1 sec
func() has been called 36 times
Got 204 signals
Got 7 signals during connect()