New smaller (file size) and matching color/styles to skin.

Files updated/improved?

* OSDProgress/Back/Mid/Light.png which covers all UI volume/progress
bars
* ScrollbarH/H_bar/H_bar_focus.png which covers all Horizontal
scrollbars
* ScrollbarV/V_bar/V_bar_focus.png which covers all Vertical scrollbars
* Tweaked all OSDfooFO.png to match closer the blue color of confluence.
All these really had far too different shades

A Textures.xbt for testing if anyone wants,
https://github.com/uNiversaI/Test/raw/master/Textures.xbt

Further texture color tweaks

Revert floor.png scrollbar bg/progress outline. Floor.png is original untouched.

No scrollbar blue bg even though even though original unmodified was
blue too  color was #b7e6fb and now its # 1a1d1f which is dark grey.

Tweaked the progress bar outline color to much faded shade now.

Updated Test Textures.xbt to match this commit and all other changes.

Final tweak to OSDProgressBack/MID

Outline is now moot #b4b4b4 which is one of the confluence colors from
defaults.xml

The progress buffering back is improved
Scrollbar back and focus is improved less transparency in texture.

Perhaps a little fainter but now gets really matching