Apertium RDF - Provenance info per dictionary

[jogracia]

Currently, provenance information in Apertium RDF is common to all the lexical entries, translation sets, and lexicons, through:
... dc:source <https://github.com/apertium/apertium-trunk.git> ;
I'd recommend to indicate the provenance per bilingual dictionary instead, e.g.:
... dc:source <https://github.com/apertium/apertium-afr-nld> ;
In that way, more interesting queries can be formulated, for instance to discover the degree of overlap between dictionaries, or the amount of links to lexinfo per bilingual dictionary (that will be needed to document them in the LLOD cloud)