Conditional -> GUIObject and make all gui objects children of GUIObject

Signed-off-by: Vojtech Bocek <vbocek@gmail.com>

Change-Id: Ic0a7d6354dabe5919b83942f2f1aa0715625e522
diff --git a/gui/slidervalue.cpp b/gui/slidervalue.cpp
index d369ace..c83456b 100644
--- a/gui/slidervalue.cpp
+++ b/gui/slidervalue.cpp
@@ -25,7 +25,7 @@
 #include "rapidxml.hpp"
 #include "objects.hpp"
 
-GUISliderValue::GUISliderValue(xml_node<>* node) : Conditional(node)
+GUISliderValue::GUISliderValue(xml_node<>* node) : GUIObject(node)
 {
 	xml_attribute<>* attr;
 	xml_node<>* child;