Button: Class ui-input-btn for all input buttons instead of ui-submit. Adjusted rules for buttons in field containers.
Core: Cleaned up and reduced CSS.
Moved label style to core.css.
No longer add the widget class to label element. Moved style for labels in field containers to fieldcontain.css.
Rangeslider: Use CSS instead of JS to hide the second label.

The second handle gets the aria-labelledby attr; the label should be accessible for screen readers.
Rangeslider: center the sliders correctly when inside a field container.
Fieldcontain: Centralize all CSS for field containers.
Fieldcontain: No need to take form wrapper into account.

The fieldcontain JS that makes it possible that label and form element are 100% width together looks for immediate children only. So things will break anyway if there is a form wrapper inside the field container.
Textinput: Only add class ui-input-text to the wrapper. Cleaned up CSS. Reduced JS.
Changed the order of the CSS to reveal possible specificity issues when using Download Builder.
Fieldcontain: Made sure button, textarea and flip toggle works.
Slider, Rangeslider: Updated CSS after changes in textinput.
Slider: Keep the flip switch native select element accessible for screen readers.
Table CSS indent and whitespace.
Switching from px to em values for padding and positioning.
Core: moved clear button and buttons in grids rules to the files where they belong.
Button: Don't use diplay none to hide the native input when disabled, because this makes a difference for screen readers.