per effect smoothing

[redPanther]

1. Tell us something about your changes.
this pr adds ability to set per effect smooting settings.
Smoothing settings are written in effect json file.
As default all effects without smoothing params in json config have smoothing disabled.

Currently I added smoothing settings only to effect "candle" and "random".
(others should follow, but I don't feel in a artistic mood today. Feel free to post settings for a specific effect as comment to this pr.)

new candle.json

{
	"name" : "Candle",
	"script" : "candle.py",
	"args" :
	{
		"sleepTime" : 0.20,
		"brightness" : 100,
		"color" : [ 255, 138, 0 ],
		"candles" : "all",
		"smoothing-custom-settings" : true,
		"smoothing-time_ms" : 500,
		"smoothing-updateDelay" : 0,
		"smoothing-updateFrequency" : 20.0,
		"smoothing-pause" : false
	}
}

Additionaly:

• refactored some qt vs. stl stuff (mainly std::min/max to qMin/Max).
• fixed fade.py effect (crashed with div by zero)

2. If this changes affect the .conf file. Please provide the changed section

3. Reference an issue (optional)
#447

[penfold42]

Perfect !

Great work

[brindosch]

Very cool!
You can hide options by adding a dependency

			"options": {
				"dependencies": {
					"smoothing-custom-settings": true
				}
			},

So this option won't be shown until smoothing-custom-setting is true

[redPanther]

cool I always wanted such option :-) it's integrated now

[redPanther]

testbuild complete. from my side ready to merge. We can add custom smoothing settings to other effects later on ...

[brindosch]

I have a question, is there a real diff between "enabled" and "pause" during usage? If you disable it, it is on kind of pause anway?

[redPanther]

pause is internal for effects and enable is for the user.
technically pause feeds the smooth device and enabled does it not.

We can rename 'pause' in 'enabled' in effects json ... this would look a bit nicer for users.

[brindosch]

So it does simply the "same". I think a merge is useful to reduce size!