Add queue_size=5 parameter to all publishers to avoid the WARN on Indigo

SyntaxWarning: The publisher should be created with an explicit keyword
argument 'queue_size'. Please see
http://wiki.ros.org/rospy/Overview/Publishers%20and%20Subscribers for
more information.

@mikeferguson, I add this to hydro-devel as we don't have still an indigo branch, but I have no problem doing otherwise, that is, create an indigo branch and add all oncoming changes there. Up to you!.