Add display of current value to slider parameters

[z3dev]

Expected Behavior

As the slider is changed, show the value of the slider.

@gilboonet suggests "An option to show/hide slider value would be great."

Actual Behavior

The slider is shown but there's no display of the current value.

Steps to Reproduce the Problem

1. Open the example call "All Parameter Types"
2. There slider can be moved but there's not value displayed.

Specifications

• Version: All
• Platform: Web UI
• Environment: Browsers

[gilboonet]

When I tweaked the old version (0.4 if I recall correctly) of openjscad to customize parameters, I added sliders with value, and also dual slider that allow to specify an interval, but my solution was ugly : I used bootstrap controls that replaced a text parameter and feed its value. And it needed javascript code to init the bootstrap controls with parameters names. And to be able to do that I needed to add name property to parameters class. This allow me to easily be able to use json to read/save parameters with name=value couplets. I can fetch my old code if it can be useful, but it was before I use github.