Impossible to set 'Quality' in command line application

[Svarov-RZM]

Description
By some reason, the '-Q' switch was removed from the command line application (synfig), so it's no longer possible to set quality of the animation. You can restore it easily, since all the functionality is still in place.

But I was wondering, does setting 'Quality' affects anything after engine switch? I remember it did back in the day, so I am not sure if we should restore in back for command line application, or remove it from GUI for consistency.

To Reproduce
Just try to render any animation with '-Q 6' option, like so: synfig.exe -Q 6 --time 0f C:\MyCoolAnimation.sif, synfig will bail out with: "Exception: Unknown option -Q"

Expected behavior
To render animation with specified quality or at least silently ignore it.

[rodolforg]

Quality parameter only affects some of those layers that weren't ported to Cobra Renderer yet.
The less the value the better quality (0 means the best).

[Svarov-RZM]

Quality parameter only affects some of those layers that weren't ported to Cobra Renderer yet.

I see. Then I think it's better to restore the '-Q' switch.
When no layers remained to be ported to Cobra, we remove it along with the GUI entry.