terminating the build takes five seconds on Windows

Terminating the build takes five seconds on Windows.
This is how we're trying to terminate the process:

• We call QProcess::terminate() which sends WM_CLOSE to the windows of the process. This has basically no effect for console processes.
• We're waiting five seconds.
• We call QProcess::kill().

On Windows, the first two steps are useless. We're always doing a useless wait and then kill our console process.

What we should do instead is sending Ctrl-C to the child process.