Library layout clean ups

[22degrees]

Not a bugfix but a bit love to the library section.
Reset the default margins to zero and make it more styleable via qss.
Some commits breaks the skins a little bit. But if required, I would fix it.

Please review.

[daschuer]

Thank you for the Pull request. I have just tested it and IMHO some changes are improvements others not. The Buttons are now stacked together which looks odd. Why is the change required?

[daschuer]

What happens if you apply a css margin?
Can we add a default margin, that is overridable by css, without breaking existing skins?

[22degrees]

Thanks for your feedback.

My personal opinion is:

• all skin elements have no margins, paddings or spacings by default
• the designer add these values as required via qss
• it is easier to set a value via css as to make time-consuming experiments to find the right property for an override

Sure, it is possible to reset the defaults via qss. You have already mentioned it.
But I didn't find any workable solution to override the layout Spacing in the LibrarySection with "qproperty-layoutSpacing: 0;" or the hardcoded spacer.

I agree that the existing skins look odd with these changes, but my skin looks great now ;)
(screenshot attached) and the skins can be quickly fixed.

I make a fix for the existing skins in the next few days.

regards Hendrik

[22degrees]

I think the existing skins are fixed and they look like before.
Attached you will find screenshots.

[daschuer]

Nice, thank you for the work. LGTM

@esbrandt and others: Any other comments before merge?

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[22degrees]

Thanks for review.
Agreement subscribed.

[daschuer]

I would like to add your real name to the contributor list in the AboutBox inside Mixxx.
Is this OK for you?

[22degrees]

That's ok!

[daschuer]

Done:
1b1a5f0