Improve transformer - Githubissues

Makes some long needed updates to the transformer setup:

[x] Change transformer class into a function to make it more flexible.
[ ] Add the transformer as a parameter on the connection to allow customisation.
[ ] Add the option to make the transformer more transparent (return all Neo4j objects unmodified) - fixes #122
[ ] Change the return type of query methods to match the return type of the transformer - should fix #119

jamesfer / cypher-query-builder