Fix volume slider behavior

[sparky8251]

Volume sliders now adjust volume when dragged (used to to only work when you stopped clicking).

Fixes #113

[sparky8251]

Hmm... I guess this isn't properly complete yet. Further testing has shown that just plain clicking is no longer enough to adjust volume.

I'm not well versed in JS, can I add the original click event to nowPlayingVolumeSlider.addEventListener("mousemove", function () { so its effectively an OR?

And since Android also relies on jf-web, It will need testing before we want to merge this in.

[cvium]

I'm not well versed in JS, can I add the original click event to nowPlayingVolumeSlider.addEventListener("mousemove", function () { so its effectively an OR?

You can add as many event listeners as you want with separate calls eg.

nowPlayingVolumeSlider.addEventListener("mousemove", function () {
    dostuff();
});
nowPlayingVolumeSlider.addEventListener("click", function () {
    dostuff();
});

[sparky8251]

This now works as one would expect on web. I am positive it will work as expected on Android, but I would sleep better if @dkanada or @thornbill would test this PR first.

Now ready for full review if anyone has been holding off!

[JustAMan]

Code seems functionally fine.
Waiting to see response on my feedback on de-uglification before stamping approval.

[JustAMan]

Please answer my de-uglification comments as well.

[sparky8251]

Pending responses to my questions. Changes marked resolved are now pushed or were tested and they broke things.

Also, confirmed that there does not appear to be a bug with slider behavior like I originally thought. Once the suggested changes are in place this is mergable imo.

[JustAMan]

LGTM pending answer to a couple of unresolved conversations.
They could be safely ignored for now if wanted, though, as they're minor in a sense.

[sparky8251]

Ok. All suggestions by @cvium and @JustAMan have been tested and implemented.

I haven't tested with this Android, but it works perfectly with FF and Chrome.

If no one has any other suggestions, I'd say this is ready for merge.