fix bug: EDA_ITEM::m_forceVisible not initialized in constructor.

common/base_struct.cpp

@@ -87,6 +87,8 @@ void EDA_ITEM::InitVars()
     SetTimeStamp( 0 );      // Time stamp used for logical links
     m_Status    = 0;
     m_Selected  = 0;        // Used by block commands, and selective editing
+    m_forceVisible = false; // true to override the visibility setting of the item.
+
 }