Compile for Windows subsystem on Windows OS

Currently, our executable is compiled for the console subsystem (aka `/SUBSYSTEM:CONSOLE` in terms of MS linker). This means it will open a console window when started, which is not wanted for a casual player.

I suggest us to do otherwise.

1. Write most of the output to a log file by default
2. Compile our Windows binary for Windows subsystem
3. On startup, detect if there's an associated console available, and use it for console-only output

As a note, I believe IntelliJ's new cross-platform launcher currently behaves like this.