[RFC] Clock + Volume sliders in top right

[Birdulon]

Attempts to add a little bit of convenient GUI parity from in-game to the lobby, in the form of main+music volume sliders and a clock.

I'll probably need to modify gui_settings_window.lua to refresh its Menu Music Volume slider, and I'll strip a lot of the commented out code before it's ready to merge, but for now I'd like some advice on making it fit the layout properly. As-is, I had to settle on what felt like hacky position values to get it to sit roughly where I wanted it, but I suspect there's a proper way of making it conform.

[GoogleFrog]

Turn the interface_root Controls into Panels so they draw as rectangles, then you can better see the structure of the menu. My recollection is that the button on the top right are in a control with the username, so it would make sense to put the volume control there.

On the slider itself, I become more concerned about the top right of the screen having too much packed into it. I have considered making Settings and Friends main menu options and turning the remaining big texty buttons into icons. The 'Home' button is redundant with the home button in the community tab and the logout button could become more integrated with the username, and look less like the big X in the top right of the application.

[Birdulon]

Hacked around with it a bit more and got it looking like this (haven't committed yet as of this comment). Is this in line with what you were thinking?

[GoogleFrog]

That is insufficiently all-encompassing.

[GoogleFrog]

I've been thinking something like this:

Basically, the top right is a mess and needs a redesign. Maybe in that redesign there would be space for volume sliders. I don't want to pile issues onto it before the redesign is underway.