office 2003——office 2007 mime 类型
.dotx,application/vnd.openxmlformats-officedocument.wordprocessingml.template
.docx,application/vnd.openxmlformats-officedocument.wordprocessingml.document
.xlsx,application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
.pptx,application/vnd.openxmlformats-officedocument.presentationml.presentation
.doc,application/msword
.dot,application/msword
.xls,application/vnd.ms-excel