adding functions for coursedownload in httpserver, specifically adding init method which is used for read info about course download from sqlite, adding class of Course,Chapter,File
merge from origin/release
ading two forms, CourseDownloadTips and CourseDownloadListForm
modify CourseDownloadTips
Merge remote-tracking branch 'origin/release' into zhangjc
fix httpRemoteServer for supporting http request with range attribute
fix bug for updatepassword
fix error in updatepassword and registe interface
merge from origin/release
cmt