Uses feature detection to determine if the running client browser is Internet Explorer 11.

/**
 * Uses feature detection to determine if the running client browser is Internet Explorer 11.
 *
 * @link https://stackoverflow.com/a/21825207
 * @return {boolean} Returns true if IE11, otherwise false.
 */
var isIE11 = !!window.MSInputMethodContext && !!document.documentMode;