This PR does a number of minor cleanups to the code in here. In particular:

* Update the README files to be a bit more accurate
* Remove dead code
* Remove rosdoc configuration (this will never be used in ROS 2)
* Remove unnecessary Python configuration (we use ament for python installation in ROS 2)
* Fix some style issues that would be pointed out by the linters


Signed-off-by: Chris Lalancette <clalancette@openrobotics.org>