replacing confluence-style waring blocks with 'note' docbook sections

(cherry picked from commit 8364f945de5e0198372e885c0af41d5840f42dec)

git-svn-id: https://svn.apache.org/repos/asf/cayenne/main/branches/STABLE-3.1@1555532 13f79535-47bb-0310-9956-ffa450edef68
updating copyright year

(cherry picked from commit ac5207877e4e6ac22f6a15ff9d2e2116011a7497)

git-svn-id: https://svn.apache.org/repos/asf/cayenne/main/branches/STABLE-3.1@1555533 13f79535-47bb-0310-9956-ffa450edef68