Desktop file
evaluate the type of the OSC argument *once*
double check that int32 types are not out-of-range

on 64bit architectures, Python's "int" type is 64bit long, but
struct.pack('i') requires 32bit, so we need to double check
fixing start/stop record

- /timestamp gives a tuple, so we must not use [t f]
- timestamp-logic for stop-record must know what is "now"