#290 local_user_urls can't locate msoffice extensions locally

[Manoj Agarwal]

If local_urls_only is set to true, and local_user_urls is used, then extensions that are searchable as local filesystem access are .html, .htm, .txt, .asc, .ps, .eps and .pdf. Can't we add .doc, .xls, .ppt, .docx, xlsx, pptx extensions also, so that these documents are also looked from local filesystem instead of going to http.