Add clarification that plugin install only need happen once
Add clarification that plugin install only need happen once

git-svn-id: 36dcc065b18e9ace584b1c777eaeefb1d96b1ee8@202225 13f79535-47bb-0310-9956-ffa450edef68

apache/forrest,apache/forrest,apache/forrest,apache/forrest,apache/forrest,apache/forrest