Issue #127 - Add validation queries for use with rdf-validator which
checks a data source against the requirements CubiQL makes on data cubes.

The queries are templates which expect the relevant configuration values
to be provided when executed.

Add instructions to the README on running these validations.

1. There is a code list that contains ONLY the concepts used at the cube
2.There is a code list for each qb:DimensionProperty

Move the comments for the dimension validation queries to the end of
of the file. Comments before the query cause sesame to infer the
wrong query type (i.e. a graph query instead of a tuple query) which
results in the wrong accept headers being sent to the remote SPARQL
endpoint.