bqackport of 1.73: In MachoPython, don't simulate argc/argv unless we have argc=1 and argv[1] starts with "-psn_". This means the drag-and-drop continues to work as expected, but we can now also do /Applications/Python.app/Contents/MacOS/python script.py from the command line, which is a lot easier with debugging. Pressing <option> at this point also has the expected effect of opening the options dialog!