Create endpoint handler to produce output for the batch importer

[Vince Bickers]

It should be possible to create a handler that outputs data into two sets of files. The first set of files representing the nodes to be inserted and the second the edges between them. This is the format used by Neo4j's command line batch importer, which is allegedly faster than the standard batch inserter bundled with the Neo4j kernel.

We would need to do some work, primarily sorting and merging of data, to get it into the form needed by the batch importer. Its possible that the overhead of doing this would eclipse any speed gained.

[Vince Bickers]

Turns out this is a) quite difficult to do properly, b) not very useful.