Use more relevant macros in wxPropertyGrid

include/wx/propgrid/propgrid.h

@@ -2041,7 +2041,7 @@ public:
 
     wxPGProperty* GetMainParent() const
     {
-        wxASSERT(m_property);
+        wxCHECK_MSG(m_property, NULL, "Property cannot be NULL");
         return m_property->GetMainParent();
     }
 

src/propgrid/propgrid.cpp

@@ -5618,7 +5618,7 @@ void wxPropertyGrid::HandleKeyEvent( wxKeyEvent &event, bool fromChild )
     // Handles key event when editor control is not focused.
     //
 
-    wxCHECK2(!IsFrozen(), return);
+    wxCHECK_RET(!IsFrozen(), "wxPropertyGrid shouldn't be frozen");
 
     // Traversal between items, collapsing/expanding, etc.
     wxPGProperty* selected = GetSelection();