REPO-3944 Renditions: Disabling the local transform switch should not disable the transform server (#236)

Problems found in caches in the ThumbnailService caused this to take place. TransformerDebug has also been improved to include Transform Service requests and responses.

src/test/java/org/alfresco/repo/thumbnail/ThumbnailServiceImplTest.java

@@ -1235,6 +1235,7 @@ public class ThumbnailServiceImplTest extends BaseAlfrescoSpringTest
     {
         ThumbnailRegistry thumbnailRegistry = this.thumbnailService.getThumbnailRegistry();
         List<ThumbnailDefinition> defs = thumbnailRegistry.getThumbnailDefinitions(MimetypeMap.MIMETYPE_HTML, -1);
+        assertFalse("There should be some thumbnails", defs.isEmpty());
         System.out.println("Definitions ...");
         for (ThumbnailDefinition def : defs)
         {