Remove Makefile-Linux-Mono so that it can be re-added as text per .gitattributes
Remove Makefile-Linux-Mono so that it can be re-added as text per .gitattributes

ClareMSYanGit/Open-XML-SDK,tomjebo/Open-XML-SDK,modulexcite/Open-XML-SDK,KuPai32G/Open-XML-SDK,ThomasBarnekow/Open-XML-SDK,OfficeDev/Open-XML-SDK,KuPai32G/Open-XML-SDK,EricWhiteDev/Open-XML-SDK,syediddi/Open-XML-SDK,syediddi/Open-XML-SDK,tarunchopra/Open-XML-SDK,EricWhiteDev/Open-XML-SDK,modulexcite/Open-XML-SDK