Address crash in Excel 2007 (#9456)
* Excel: use LresultFromObject and objectFromLResult to marshal cell range objects between NvDA and nvdaHelper inproc code, rather than letting Windows do it, as the previous implementation was failing on Office 2007 because CoInitialize was never called on the RPC worker thread.
* use null for wParam.
* Marshal Excel cell ranges by using the Excel cell address.
* Update what's new.
