got rid of legacy RDF types, reusing those of Data.RDF
using OverloadedStrings to get rid of "pack" calls
using Text for Prefix arguments
got rid of obsolete Data.String.Utils
IRIRef is back?
applied robstewart57's "Added-AbsoluteIRI-constructor-in-IRIRef-and-changed-" patch
some DRYing
resolved merge conflicts