Enable Tycho's versions plugin

[1] http://www.eclipse.org/tycho/sitedocs/tycho-release/tycho-versions-plugin/plugin-info.html
Next development version is 2.0.0-SNAPSHOT

Next time, use tycho-versions-plugin to modify versions like:

    mvn org.eclipse.tycho:tycho-versions-plugin:set-version -DnewVersion=2.0.0-SNAPSHOT
Drop examples
Switch to Neo4J 2.0.0

Require JavaSE-1.7 Execution Environment as, since Neo4J 2.0, Java 6
is no longer supported.
Use GraphDatabaseBuilder instead of EmbeddedGraphDatabase
Replace Config.ALLOW_STORE_UPGRADE with GraphDatabaseSettings
Honor 'allow store upgrade' option

But for local DB only as RestGraphDatabase doesn't provide such
feature.
Merge pull request #59 from manandbytes/next-dev-version

Switch to Neo4J 2.0.0