[bridges] Rename bridges that are missing 'Bridges'

The word 'Bridge' is a requirement for the filename and class name.
Also documented here (now):
https://github.com/rss-bridge/rss-bridge/wiki/how-to-create-a-new-bridge

bridges/FreenewsBridge.php

@@ -1,6 +1,6 @@
 <?php
 define("FREENEWS_RSS", 'http://feeds.feedburner.com/Freenews-Freebox?format=xml');
-class Freenews extends RssExpander {
+class FreenewsBridge extends RssExpander {
 
 	public function loadMetadatas() {
 

bridges/GawkerBridge.php

@@ -2,7 +2,7 @@
 define("RSS_PREFIX", "http://feeds.gawker.com/");
 define("RSS_SUFFIX", "/full");
 
-class Gawker extends RssExpander{
+class GawkerBridge extends RssExpander{
 
     public function loadMetadatas() {
 

bridges/Les400CulsBridge.php

@@ -2,7 +2,7 @@
 define("SEXE", "http://sexes.blogs.liberation.fr");
 define("SEXE_FEED", "http://sexes.blogs.liberation.fr/feeds/");
 
-class Les400Culs extends RssExpander{
+class Les400CulsBridge extends RssExpander{
 
 	public function loadMetadatas() {
 

bridges/WorldOfTanksBridge.php

@@ -1,7 +1,7 @@
 <?php
 define('WORLD_OF_TANKS', 'http://worldoftanks.eu/');
 define('NEWS', '/news/');
-class WorldOfTanks extends HttpCachingBridgeAbstract{
+class WorldOfTanksBridge extends HttpCachingBridgeAbstract{
 
     private $lang = "fr";
     public $uri = WORLD_OF_TANKS;