add method: Invoker#setup_pipe. modify method: Invoker#connect: use setup_pipe. modify method: Invoker#close_all: puts backtrace to .
add method: Invoker#setup_pipe.
modify method: Invoker#connect: use setup_pipe.
modify method: Invoker#close_all: puts backtrace to .

masa16/pwrake,masa16/pwrake2