Added test exposing how #45 is invalid : a tag defined in a different named graph can be seen as element of Post tags
Fixed #45 by ensuring all LazyLoaders now use the correct strategy idiom
As an add-on to #45, the whole queries have been re-written to use mapping stratgy, instead of direct calls to getOutEdges (which doesn't respect named graphs)
Merge remote-tracking branch 'origin/master'