Created GuiEntryListEntry interface for GuiEntryList contained classes to avoid toString() methods from having to be abused

Created GuiFileChooser and according Listeners
Added (non-functional) GuiAssetAdder for CustomImageObjects

src/main/java/eu/crushedpixel/replaymod/renderer/CustomObjectRenderer.java

@@ -38,7 +38,6 @@ public class CustomObjectRenderer {
 
         GlStateManager.disableTexture2D();
 
-        //do stuff here
         for(CustomImageObject object : ReplayHandler.getCustomImageObjects()) {
             drawCustomImageObject(doubleX, doubleY, doubleZ, object);
         }