Global layer timeout topic with height

Updated the obstacle timeout so that you can specify to clear old obstacles based on the topic

Enable this by setting the following for each sensor for which you require the obstacles to timeout (this only works for global maps) 
e.g.
bump: { clear_old: true, max_obstacle_persistance: 3.0}

Time is in seconds.

Option to enable height checking before clearing obstacle

set check_height_before_clearing : true in the voxel layer 
The implementation was moved out to the cpp file - forgot to remove the
comment.


On Sun, Aug 24, 2014 at 9:35 PM, Kaijen Hsiao <notifications@github.com>
wrote:

> In costmap_2d/include/costmap_2d/voxel_layer.h:
>
> >      std::vector<ObstaclePoint> indices;
> >    };
> >
> >    //keeps track of the last time each index location was updated
> > +  //we should move this out probably to a cpp file - lot of implemetation in the header
>
> I agree with this comment, would really like to see this stuff moved to a
> cpp file.
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/bosch-ros-pkg/navigation/pull/18/files#r16641857>.
>