[WIP] Set ROS_MASTER_URI to localhost in *robot*_play.sh

[708yamaguchi]

By this pull request, ROS_MASTER_URI is set to localhost in *robot*_play.sh. (e.g. pr2_play.sh)
This program will prevent launching rosbag play node in master robot.

Merge after #1611

[k-okada]

Did you consider writing something like

<launch>                                                                                                               
  <arg name="ROS_MASTER_URI" default="$(env ROS_MASTER_URI)" />
  <env name="ROS_MASTER_URI" value="$(arg ROS_MASTER_URI)" />
</launch>

I am not so confident, so there might be a drowback.

[k-okada]

waiting for feedback @708yamaguchi @iory