Strategy to get files and getNsp changed

Strategy to get files changed:
->test turtle first as using the openrdf library it may accept a turtle
file as RDF/XML

Strategy to get namespace changed:
->check if there is an explicit vann:preferredNamespace
->check if there is a namespace which contains the URI (Levenshtein
algorithm used to get the closest)
->Statistic approach using classes and properties namespace (most used
namespace)
->Fetch the xlmns default namespace -> most unpredictable since openrdf
library build one from nowhere