Adjust copyrights years

<?php
/**
 * SeekQuarry/Yioop --
 * Open Source Pure PHP Search Engine, Crawler, and Indexer
 *
 * Copyright (C) 2009 - 2018  Chris Pollett chris@pollett.org
 *
 * LICENSE:
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 * END LICENSE
 *
 * @author Chris Pollett chris@pollett.org
 * @license https://www.gnu.org/licenses/ GPL3
 * @link https://www.seekquarry.com/
 * @copyright 2009 - 2018
 * @filesource
 */
namespace seekquarry\yioop\library\processors;

use seekquarry\yioop\configs as C;

/**
 * Base abstract class common to all processors used to create crawl summary
 * information from images
 *
 * @author Chris Pollett
 */
class ImageProcessor extends PageProcessor
{
    /**
     * Extract summary data from the image provided in $page together the url
     *     in $url where it was downloaded from
     *
     * ImageProcessor class defers a proper implementation of this method to
     *     subclasses
     *
     * @param string $page  the image represented as a character string
     * @param string $url  the url where the image was downloaded from
     * @return array summary information including a thumbnail and a
     *     description (where the description is just the url)
     */
    public function process($page, $url)
    {
        return null;
    }
    /**
     * Used to create a thumbnail from an image object
     *
     * @param object $image  image object with image
     *
     */
    public static function createThumb($image)
    {
        $thumb = imagecreatetruecolor(C\THUMB_DIM, C\THUMB_DIM);
        imagesavealpha($thumb, true);
        $trans_colour = imagecolorallocatealpha($thumb, 255, 255, 255, 127);
        imagefill($thumb, 0, 0, $trans_colour);
        if ( !empty($image) ) {
            $size_x = imagesx($image);
            $size_y = imagesy($image);
            set_error_handler(null);
            @imagecopyresampled($thumb,
                $image, 0,0, 0,0, C\THUMB_DIM, C\THUMB_DIM, $size_x, $size_y);
            set_error_handler(C\NS_CONFIGS . "yioop_error_handler");
            imagedestroy($image);
        }
        ob_start();
        imagejpeg($thumb);
        $thumb_string = ob_get_contents();
        ob_end_clean();
        imagedestroy($thumb);
        return $thumb_string;
    }
}