Allow valueStep to be set on Slider creation

[Wutname1]

Simple addition to allow the valueStep to be set on the slider.

Example:
StdUi:Slider(parent, width, height, value, vertical, min, max)
to
StdUi:Slider(parent, width, height, value, vertical, min, max, step)

[pwilkowski]

sure but then you would have 8 arguments and that is a bit too much.
You can always set step later:

slider:SetValueStep(value)

[Wutname1]

Ya, just a suggestion since step tends to be set often.