CDN_JS: use Javascripts via CDN in WordPress. Example: define( 'CDN_JS', '//cdn.net/path/to/a.js //path/to/b.js' );

cdn_js_plugin.wordpress.php

<?php namespace Nick_Freear\WordPress;
/*
Plugin Name: CDN_JS
Plugin URI:  https://gist.github.com/nfreear/1d459d4a0a21d90d21c3
Description: Quickly use Javascripts via CDN. Example:  define( 'CDN_JS', '//cdn.net/path/to/a.js //path/to/b.js' )  [LACE]+
Author:      Nick Freear [@IET-OU]
Author URI:  https://github.com/nfreear
Version:     0.5
*/


/**
 * @copyright 2015 Nick Freear.
 * @license   MIT
 * @link      http://www.jsdelivr.com/#!anchorjs
 */


class CDN_JS_Plugin {

    protected $opt;

	public function __construct() {
		// Hook into the 'init' action
		add_action( 'wp_enqueue_scripts', array( &$this, 'enqueue_scripts' ), 20 );
		add_action( 'wp_footer', array( &$this, 'wp_footer' ), 99 );

		if (defined( 'CDN_JS_INI' )) {
			$this->opt = (object) parse_ini_string( CDN_JS_INI, $process_sections = true );
			@header('X-CDN_JS_INI: '. json_encode( $this->opt ));
		}
	}

	public function enqueue_scripts() {

		if (defined( 'CDN_JS' )) {

			$scripts = explode( ' ', CDN_JS );
			foreach ($scripts as $idx => $js) {
				wp_enqueue_script( 'cdn-js-'. $idx, $js, null, null, $in_footer = true );
			}
		}
		
		$hosts = isset( $this->opt->hosts ) ? $this->opt->hosts : null;

		if (isset( $this->opt->scripts )) {
			foreach ($this->opt->scripts as $idx => $script) {
				$js = strtr( $script, $hosts );
				wp_enqueue_script( 'cdn-js-'. $idx, $js, null, null, $in_footer = true );
			}
		}

		if (isset( $this->opt->styles )) {
			foreach ($this->opt->styles as $idx => $style) {
				$css = strtr( $style, $hosts );
				wp_enqueue_style( 'cdn-js-'. $idx, $css );
			}
		}
	}

	public function wp_footer() {

		if (!defined( 'CDN_JS_INLINE' )) return;

		?>
	<script id="cdn-js-inline">
	<?php echo CDN_JS_INLINE ?>
	</script>
<?php
	}

}
$wp_cdn_js_plugin = new CDN_JS_Plugin();


/** @example

define( 'CDN_JS', 'http://nekman.github.io/keynavigator/keynavigator.js' );


define( 'CDN_JS_INI',
'
# Demo of substitution of hosts in scripts.
[hosts]
%sm = https://cdn.rawgit.com/vadikom/smartmenus/1.0.0-beta1/src

[scripts]
sm1 = %sm/jquery.smartmenus.js
nav = https://cdn.rawgit.com/tommoor/navigate-jquery-plugin/master/jquery.navigate.js

[styles]
sm2 = %sm/css/sm-core-css.css
' );


define( 'CDN_JS_INLINE',
"jQuery(function ($) {
  $('#menu-menu-1 > li > a').navigate()
})" );

*/