change the radius of the inner bar

[Snort007]

i would like to have an extra option to change the radius of the internal bar separatly to get a smother look and feel.
the parameter bar_radius changes the frame and the bar.
e.g. it would looks more modern with a round frame, but with a 0px bar, like in the most of views I ever saw...

[Snort007]

i would like to set the internal bar radius without card mod! or fixed at 0px