remove unused plugins and add the cost cloud.
redirect all params and launchers at the real turtlebot configuration files and cleanup, #21.
stage only permits 'square' robots, so make sure our square fits within
the turtlebot defined circle otherwise it collides when it normally
wouldn't.
Merge pull request #22 from turtlebot/stage_cleanup

Sync the stage simulation with the real turtlebot configuration
add the trajectory cloud to stage's rviz view.
Merge branch 'indigo' of https://github.com/turtlebot/turtlebot_simulator into indigo
updated rviz configuration for dwa.