Generating a sample conversion using only a subset of data

Why? Faster turn-around when developing enhancement params.

How?

Set:

CSV2RDF4LOD_CONVERT_EXAMPLE_SUBSET_ONLY="yes"

.sample.ttl

TODO: example vs sample. one is explicitly annotated in the enhancement params, the other is just the first N rows. Is it being consistent? Look at java params, conversion: params, and env vars.