OAK-2232: External events incomplete

Add simpler test in oak-core
Preliminary fix

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1635077 13f79535-47bb-0310-9956-ffa450edef68
OAK-301 Document Oak

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1635079 13f79535-47bb-0310-9956-ffa450edef68
OAK-301 Document Oak

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1635088 13f79535-47bb-0310-9956-ffa450edef68
OAK-301 Fix message

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1635089 13f79535-47bb-0310-9956-ffa450edef68
Merge branch 'upstream-trunk' into OAK-2226