Fix number of arguments on `container.addSlider`

[runegan]

Original report by Remco Janssen (Bitbucket: [Remco Janssen](https://bitbucket.org/Remco Janssen), ).

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Not sure why this is a problem. Should this be converted to an options object?

Warning: 297:13 warning Method 'addSlider' has too many parameters (5). Maximum allowed is 4 max-params

See: https://bitbucket.org/motiondesign/aequery/src/4fa3668468d17139f7f52924a7b0a4c325842c71/lib/ui/container.js?fileviewer=file-view-default#container.js-297

[runegan]

Original comment by Rune Gangsø (Bitbucket: runegan, GitHub: runegan).

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Yeah, option object would be better, and it matches the api of the other addX methods.

Max params is set to 4 because it is difficult to know/nicely code all the params correctly when there are too many. I think after 4 you start struggling with line length and argument order.