Add `gds#find`

Based on feedback from @maxdemarzi, introduce a `gds#find` method that replaces `gds#findNodesByLabelAndProperty` and `ggo#getAllNodesWithLabel`.
99.9% of the time a developer is going to find a node and then explore the graph from there.  In Ruby land when something is done 99.9% of the time, we add "sugar".  Sugar is defined as a shortcut to eliminates options and does just that thing that 99.9% of the time the developer wants to do. No thinking, no options, no "future proof", no nothing. Sugar makes developers happy and that's what I'm asking for. Give me some sugar. If you want to add findWhatever later, then by all means.  I'd even like a findSingleNode method like http://neo4j.com/docs/2.1.5/javadocs/org/neo4j/graphdb/Node.html#getSingleRelationship(org.neo4j.graphdb.RelationshipType,%20org.neo4j.graphdb.Direction)