Added note about pcl_conversions.h copied into this repo
Added PCL to package.xml
Include <sdf/sdf.hh> instead of <sdf/SDF.hh>

The sdformat package recently changed the name of an sdf header
file from SDF.hh to SDFImpl.hh; this change will use the lower-case
header file which should work with old and new versions of sdformat
or gazebo.
changelogs for 2.1.5
2.1.5
Merge branch 'hydro-devel' into merge_hydro_into_groovy
Merge pull request #78 from ros-simulation/merge_hydro_into_groovy

Merge hydro into groovy
Merge branch 'groovy-devel' of github.com:ros-simulation/gazebo_ros_pkgs into groovy-devel