v2.3 - updated for WP 4.3

Per https://make.wordpress.org/core/2015/07/02/deprecating-php4-style-constructors-in-wordpress-4-3/, WP 4.3 deprecates PHP4-style widget constructors, and their usage will trigger deprecated notices. Switching to PHP5 constructors is simple and resolves the problem.

readme.txt

@@ -3,8 +3,8 @@ Contributors: ethitter
 Donate link: https://ethitter.com/donate/
 Tags: tag, tags, taxonomy, sidebar, widget, widgets, dropdown, drop down
 Requires at least: 2.8
-Tested up to: 4.2
-Stable tag: 2.2
+Tested up to: 4.3
+Stable tag: 2.3
 License: GPLv2 or later
 License URI: http://www.gnu.org/licenses/gpl-2.0.html
 
@@ -80,6 +80,9 @@ To make targeting a specific filter reference possible should you use multiple i
 
 == Changelog ==
 
+= 2.3 =
+* Update for WordPress 4.3 by removing PHP4-style widget constructor usage (https://make.wordpress.org/core/2015/07/02/deprecating-php4-style-constructors-in-wordpress-4-3/).
+
 = 2.2 =
 * Update for WordPress 4.2 to handle term splitting in the plugin's include/exclude functionality. Details at https://make.wordpress.org/core/2015/02/16/taxonomy-term-splitting-in-4-2-a-developer-guide/.
 
@@ -158,6 +161,9 @@ To make targeting a specific filter reference possible should you use multiple i
 
 == Upgrade Notice ==
 
+= 2.3 =
+Updated for WordPress 4.3. Removed PHP4-style widget constructor usage (https://make.wordpress.org/core/2015/07/02/deprecating-php4-style-constructors-in-wordpress-4-3/).
+
 = 2.2 =
 Updated for WordPress 4.2. Only version 2.2 or higher should be used with WordPress 4.2 or higher, otherwise included/excluded terms may reappear in dropdowns. This is due to WordPress splitting shared terms, as detailed at https://make.wordpress.org/core/2015/02/16/taxonomy-term-splitting-in-4-2-a-developer-guide/.
 

tag-dropdown-widget.php

@@ -4,7 +4,7 @@ Plugin Name: Taxonomy Dropdown Widget
 Plugin URI: https://ethitter.com/plugins/taxonomy-dropdown-widget/
 Description: Creates a dropdown list of non-hierarchical taxonomies as an alternative to the term (tag) cloud. Widget provides numerous options to tailor the output to fit your site. Dropdown function can also be called directly for use outside of the widget. Formerly known as <strong><em>Tag Dropdown Widget</em></strong>.
 Author: Erick Hitter
-Version: 2.2
+Version: 2.3
 Author URI: https://ethitter.com/
 
 This program is free software; you can redistribute it and/or modify
@@ -458,12 +458,12 @@ class taxonomy_dropdown_widget extends WP_Widget {
 
 	/**
 	 * Register widget and populate class variables
-	 * @uses this::WP_Widget
+	 * @uses parent::__construct()
 	 * @uses taxonomy_dropdown_widget_plugin::get_instance
 	 * @return null
 	 */
 	public function __construct() {
-		$this->WP_Widget( false, 'Taxonomy Dropdown Widget', array( 'description' => 'Displays selected non-hierarchical taxonomy terms in a dropdown list.' ) );
+		parent::__construct( false, 'Taxonomy Dropdown Widget', array( 'description' => 'Displays selected non-hierarchical taxonomy terms in a dropdown list.' ) );
 
 		// Shortcut to the main plugin instance from within the widget class
 		$this->plugin = taxonomy_dropdown_widget_plugin::get_instance();