Q: Why is that when I execute the command:
./pdfTonto -f booklet in.pdf outbooklet.pdf
nothing happens? (nothing - no output of any kind, the program hangs, there is no indication of cpu usage)

A: The program is waiting for input from the standard input. If you want it to read a file as input, you need to specify an input and output file using the flag options. Try using:
./pdfTonto -f booklet -i in.pdf -o outbooklet.pdf
or if you prefer long options
./pdfTonto --filter booklet --in in.pdf --out outbooklet.pdf
or if you want to use redirection:
./pdfTonto -f booklet < in.pdf > outbooklet.pdf