Feat/add velodyne submodule

[andrewyarovoi]

Description

This PR adds the master branch of the velodyne package as a sub module and enables the use of organized clouds to allow for more efficient calculation of normals.

This PR does the following:

• Adds the Velodyne package as a submodule
• Adds the option to enable organized clouds in velodyne_lidar.launch (false by default)

Fixes #508

Testing steps (If relevant)

1. Connect to a Velodyne puck (http://wiki.ros.org/velodyne/Tutorials/Getting%20Started%20with%20the%20Velodyne%20VLP16)
2. roslaunch igvc_platform velodyne_lidar.launch organize_cloud:="true"

Expectation: Should run normally.

Self Checklist

• I have formatted my code using make format
• I have tested that the new behaviour works

[oswinso]

changes look good to me, but we'll need to test first before merging

[oswinso]

Oh woops Wednesday we had all hands + some other stuff so we couldn't get to test it out then. Let's aim for the coming Wednesday to test this.