* By default this option is set to `false` and can be enabled using the
new `-viewonly`/`viewonly` command-line/config options.
* When enabled, none of the input modules will be initialised, making
the streaming session view-only, i.e. no input is sent to host.
To facilitate implementation, SDL initialisation with `sdl_init()` was moved
a bit earlier in the code to decouple from input initialisation.
