Make time independent tracing output by default in one file per process

Make time independent tracing output by default in one file per process
Structure is filename.txt : list of all the files to open
folder filename.txt_files : all files, with unique names (so that they won't be erased by a new run, only the main one will)

Adds an option tracing/smpi/format/ti_one_file to only use one subfile and put every event in it
For larger runs this will avoid opening too many handles.