Cleaned version of LSQ 2.0

A cleaned version of SPARQL logs information from dumps generated by the Linked SPARQL Queries (LSQ) project. See lsq-clean for description of motivation and methods. Each RDF dump contain information about either queries or their executions on a specific SPARQL endpoint and time interval, following [the original LSQ vocabulary](http://lsq.aksw.org/vocab) visually described [here](http://lsq.aksw.org/v2/concepts/data-model.html).