add AssembleScans.srv and add code for using PointCloud2

Author: applications

srv/AssembleScans2.srv

@@ -0,0 +1,9 @@
+# The time interval on which we want to aggregate scans
+time begin
+# The end of the interval on which we want to assemble scans or clouds
+time end
+---
+# The point cloud holding the assembled clouds or scans. 
+# This cloud is in the frame specified by the ~fixed_frame node parameter. 
+# cloud is empty if no scans are received in the requested interval.
+sensor_msgs/PointCloud2 cloud