[jsk_pr2_startup] change realtime_socket_timeout and max_pd_retries

[knorth55]

change the realtime_socket_timeout and max_pd_retries to 20000 and 5.
PR2 realtime loop checks the ethercat loop with timeout 20ms and retries 5 times.
PR2 stops its servo when ethercat connection return is slower than 20*5=100ms,
which is the same as previous timeout.

detailed info: http://wiki.ros.org/ethercat_hardware/Tutorials/ChangingRealtimePacketTimeout
cc. @ishiguroJSK

[knorth55]

please read here for more detailed information of pr2 realtime control.

https://github.com/PR2/pr2_ethercat_drivers/blob/kinetic-devel/ethercat_hardware/src/ethercat_hardware.cpp#L295-L340
https://github.com/PR2/pr2_robot/blob/kinetic-devel/pr2_ethercat/src/main.cpp#L289-L300

[k-okada]

@knorth55 sorry could you resolve conflicts?

[knorth55]

I resolve the conflicts.