Add some missing headers required on wx3.0 at least

common/msgpanel.cpp

@@ -32,6 +32,7 @@
 
 #include <wx/dcscreen.h>
 #include <wx/dcclient.h>
+#include <wx/settings.h>
 
 
 BEGIN_EVENT_TABLE( EDA_MSG_PANEL, wxPanel )

common/rc_item.cpp

@@ -24,6 +24,7 @@
 
 #include <wx/wupdlock.h>
 #include <wx/dataview.h>
+#include <wx/settings.h>
 #include <widgets/ui_common.h>
 #include <marker_base.h>
 #include <eda_draw_frame.h>

common/status_popup.cpp

@@ -26,6 +26,7 @@
  * Transient mouse following popup window implementation.
  */
 
+#include <wx/settings.h>
 #include <status_popup.h>
 #include <eda_draw_frame.h>