OAK-651 - added constructors to instantiate configuration and server providers

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1449692 13f79535-47bb-0310-9956-ffa450edef68
OAK-651 - added constructors to instantiate server provider

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1449693 13f79535-47bb-0310-9956-ffa450edef68