OAK-782: MemoryNodeBuilder.setNode() loses property values

The base state of MutableNodeStates should follow that of the parent writeState instead of the base state of the parent builder.

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1469277 13f79535-47bb-0310-9956-ffa450edef68