OAK-301: Document Oak
Document write skew issue

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1595952 13f79535-47bb-0310-9956-ffa450edef68
OAK-301: Document Oak
Remove link to Wiki

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1595953 13f79535-47bb-0310-9956-ffa450edef68