Parser for the SPV format as provided by IBM SPSS
With many thanks to GNU:
https://www.gnu.org/software/pspp/pspp-dev/html_node/SPSS-Viewer-File-Format.html
This parser is intended to parse data provided in SPSS Viewer (.spv), here called SPV files, as written by SPSS 16 and later which represent the contents of its output editor.
The output is provided in JSON for further transformation and utilization by the consumer of this library