Ctrl+C in cpp_client result in error "Assertion failed: Successful WSASTARTUP not yet performed"

[sashafrey]

This is a regression, introduced in alfrey_rpcz branch. If one press Ctrl+C to abort cpp_client during ongoing processing, he gets an error message:

Assertion failed: Successful WSASTARTUP not yet performed (......\src\signaler
.cpp:328)

As far as I see, there is no simple way of solving this on Windows. On Linux this can be handled by calling install_signal_handler() method from src\rpcz\include\rpcz\connection_manager.hpp.

I hope this is an annoying, but harmless error. However, there might be some consequences - for example, leaking socket connections when clients crash, etc. So I suggest we ignore this ticket for now, but keep it open as a reminder.