added README
added README

git-svn-id: 2f5e475bdf4c9f93a32f8df32b4f76f61e23e272@6149 4f504ea5-f356-0410-adec-f1b3679f3bb7

chen0510566/ach,golems/ach,chen0510566/ach,golems/ach,golems/ach,chen0510566/ach,chen0510566/ach,chen0510566/ach,golems/ach,golems/ach,chen0510566/ach,golems/ach