Log Message:-----------add doc for user
Added Files:----------- src/externaltable/doc: 外部表使用文档.doc (r1.1) (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgexternaltable/src/externaltable/doc/外部表使用文档.doc?rev=1.1&content-type=text/x-cvsweb-markup)