Cleaning up the VoID support.

* [DC,SC] Removed this module, never used.
* [FOAF,SC] Removed this module, never used.
* [META_EXT,DEB] Option 'A' shows less debug messages and shows the percentage i.o. the raw number of items processed.
* [VOID,SC] Split the void module into void file handling, reading from void, and void statistics.
* [VOID,SC] Removed the RDF/XML serialization of the VoID vocabulary, the Turtle serialization suffices.
* [VOID_FILE,VOID_STAT,SC] Stabilizing the new VoID modules.