User setting for beat slider in viewer

[BreakfastMan]

The older viewer (like 2.X) had two sliders: one for stuntsheets and the other for beats.

This might just be the old person in me talking but I have a strong preference for the old layout. Knowing I'm on beat 156 out of 296 isn't that useful. I'd rather know I was on beat 20 of stuntsheet 5.

Would it be feasible to make this a user setting, so I could use the old one? I think the horizontal layout can stay the same but cut the space for the slider in two and put both sliders. Sheet first than beat.

[rmpowell77]

Fixed in #688. There's a setting in preference to enable this.