space-time view and associated tools for Paje trace files

 PajeNG (Paje Next Generation) is a re-implementation (in C++) and
 direct heir of the well-known Paje visualization tool for the
 analysis of execution traces (in the Paje File Format) through trace
 visualization (space/time view). Auxiliary tools are also available
 to dump to CSV and validate the correctness of Paje trace files.