常见文件的http中content-type头的值(MIME类型)
采集日期：2008-4-26作者：addyou(注：本数据由系统自动采集，内容与BHCODE无关)
.ai - application/postscript.aif - audio/x-aiff.aifc - audio/x-aiff.aiff - audio/x-aiff.asc - text/plain.au - audio/basic.avi - video/x-msvideo.bcpio - application/x-bcpio.bin - application/octet-stream.c - text/plain.cc - text/plain.ccad - application/clariscad.cdf - application/x-netcdf.class - application/octet-stream.cpio - application/x-cpio.cpt - application/mac-compactpro.csh - application/x-csh.css - text/css.dcr - application/x-director.dir - application/x-director.dms - application/oct