bad node names in rospy tutorials launch

[tfoote]

rospy_tutorials/003_listener_with_user_data$ roslaunch listener_with_user_data.launch

WARNING: WARN: illegal <node> name 'talker-1'.
http://ros.org/wiki/Names
This will likely cause problems with other ROS tools.
Node xml is <node args="chatter:=chatter1" name="talker-1" pkg="rospy_tutorials" type="talker"/>
WARNING: WARN: illegal <node> name 'talker-2'.
http://ros.org/wiki/Names
This will likely cause problems with other ROS tools.
Node xml is <node args="chatter:=chatter2" name="talker-2" pkg="rospy_tutorials" type="talker"/>
WARNING: WARN: illegal <node> name 'talker-3'.
http://ros.org/wiki/Names
This will likely cause problems with other ROS tools.
Node xml is <node args="chatter:=chatter3" name="talker-3" pkg="rospy_tutorials" type="talker"/>

[tfoote]

Also a problem in 004 and 006.