Updated ros-pkg for RTAB-Map 0.8.0

Moved all nodelets and rviz plugins in "rtabmap_ros" namespace instead of "rtabmap"
Refactored rtabmap_ros messages (added convenient conversion methods in rtabmap_ros/MsgConversion.h)
Added noise filtering parameters for map_assembler node
Added variance parameter for map_optimizer node
Odometry nodes publish covariance matrices in odometry messages. Publish rtambap_ros::OdomInfo topic too.

src/nodelets/data_odom_sync.cpp

@@ -39,7 +39,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <sensor_msgs/CameraInfo.h>
 #include <nav_msgs/Odometry.h>
 
-namespace rtabmap
+namespace rtabmap_ros
 {
 
 class DataOdomSyncNodelet : public nodelet::Nodelet
@@ -126,5 +126,5 @@ private:
 };
 
 
-PLUGINLIB_EXPORT_CLASS(rtabmap::DataOdomSyncNodelet, nodelet::Nodelet);
+PLUGINLIB_EXPORT_CLASS(rtabmap_ros::DataOdomSyncNodelet, nodelet::Nodelet);
 }