wxSlider event handling as described by Vadim in thread 'Slider events' at wx-dev. More changes towards wxRadioBox on Palm.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@31852 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/palmos/slider.h

@@ -85,8 +85,9 @@ protected:
 private:
 
     void Init();
-    int m_oldPos;
-    int m_lineSize;
+    int m_oldPos;    // needed for tracing thumb position during scrolling
+    int m_oldValue;  // needed for comparing thumb position before and after scrolling
+    int m_lineSize;  // imitate line size
 
     DECLARE_DYNAMIC_CLASS_NO_COPY(wxSlider)
 };