On Windows the socket library must be initialized before use

This should fix GUI vu meter on Windows

+ fixed icon (it was previously put to the bundle without GUI)

Exit with non-zero return code if GUI build fails.

Fixes the bug that limited the maximal number to 2.

Refer to commit b45bb22c

Template parameter was dubious under MSW (unable to deduce).

This behaves better with Wayland backend.

Fixed missing console output caused by -mwindows flag from SDL2
pkg-config.

Added options to:
- choose driver and renderer
- disable sync on VBlank