Allow TurtleParser output into file

[lehmann-4178656ch]

Allow redirection of the generated .nt formated data without the inclusion of status messages printed to stdout like:

INFO:  mapping 2639242643 bytes
INFO:  Parsing of line has Failed, but parseInput is not yet exhausted. Remaining bytes: 1
INFO:  Logging first 1000 unparsed characters

These messages remain on stdout.

[niklas88]

This is my mistake as I literally typed the method name but we are using camel case for methods and therefore it should be "writeNT()". Other than that this looks good to me

[niklas88]

LGTM