Merge pull request #16 from amorgner/master

Use 1.9-SNAPSHOT
upgrade to neo4j 1.9
[maven-release-plugin] prepare release 0.6-neo4j-1.9
[maven-release-plugin] prepare for next development iteration
Fix for excessive growth of r-tree nodes, now whenever current node count is equal or _more_ than maxNodeReferences it will split and rebalance
Upgrade to use with neo4j 1.9.5