Changed NIF test cases

I documented all my changes in the individual commits. (Git messed up the comments, they all started with for i in `ls` )
1.  removed sourceUrl and anchorOf-> sourceUrl is not an important information  for the NLP tool, thus unnecessary, anchorOf is redundant as well 
2.  renamed nif:convertedFrom/nif:wasConvertedFrom
3.  added begin and end index
4. I also reformatted the blank nodes using the turtel [] notation

I was reluctant to remove wasConvertedFrom, it seems difficult to recreate. It is optional though.  Removable with:
 for i in `ls` ; do  sed 's/nif:wasConvertedFrom.*//' $i  ; done