///
/// Disables selection of content of a given element.
///
/// @author drublic
///
/// @link http://caniuse.com/user-select-none caniuse
/// @link https://developer.mozilla.org/en-US/docs/Web/CSS/user-select MDN
///
/// @param {none|auto} $value [none] - optional
///
/// @output
/// ```css
///   -webkit-user-select: <value>;
///      -moz-user-select: <value>;
///       -ms-user-select: <value>;
///           user-select: <value>;
/// ```
///
/// @example
///   .selector {
///     @include x-user-select;
///   }
///
@mixin x-user-select ($value: none) {
	-webkit-user-select: $value;
	   -moz-user-select: $value;
	    -ms-user-select: $value;
	        user-select: $value;
}