OAK-1502 - Make DataStores available to NodeStores

-- Removed earlier way of configuring BlobStore/DataStore via system property/config with OSGi config
-- Introduced specific OSGi components for various types of DataStore and BlobStore such that they can be configured via OSGi

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1577447 13f79535-47bb-0310-9956-ffa450edef68