mandatory transactions for all calls to GraphDatabaseService
still to do: node and relationship facades, index and schema
Merge pull request #992 from lassewesth/mandatorytx_firstslice

mandatory transactions for all calls to GraphDatabaseService
Ensure transaction state instantiated lazily for all non-mutating operations.
Added await condition when starting cluster
Merge branch '2.0' of github.com:neo4j/neo4j