getSpreadableProps util

[levithomason]

A util for getting spreadable props, to handle this use case:

let checkboxProps = _.clone(this.props);
delete checkboxProps.settings;  // all modules need to do this
delete checkboxProps.className; // this would be passed in

// then

<input {...checkboxProps} />

We need to remove props.settings from all Semantic UI Modules. Also, many components need to exclude certain props from being spread as they belong elsewhere. Like the checkbox example above, and this message example:

let messageProps = _.clone(this.props);
delete messageProps.icon;

// then

<div {...messageProps}>

The icon prop belongs as classes on the icon inside the message, then the rest of the props are spread.

This should be abstracted away with a util that understands what to do to get spreadable props.

[levithomason]

Lack of this util is also currently resulting in double rendered children. The children are rendered once by the parent component, but also the props.children are spread onto the component, so they are rendered twice.