No changes, just slightly simplify the tool insertion code.

Added a helper DoInsertNewTool() function to avoid code duplication and ensure
that we never forget to delete a new tool if inserting it into the toolbar
failed.

Also explicitly document that the tool passed to the public InsertTool() is
not owned by the toolbar and so must be deleted by the caller if its insertion
failed.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@62846 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/toolbar.h

@@ -533,6 +533,10 @@ public:
         You must call Realize() for the change to take place.
 
         @see AddTool(), InsertControl(), InsertSeparator()
+
+        @return The newly inserted tool or @NULL on failure. Notice that with
+            the overload taking @a tool parameter the caller is responsible for
+            deleting the tool in the latter case.
     */
     wxToolBarToolBase* InsertTool(size_t pos, int toolId,
                                   const wxBitmap& bitmap1,