Revert "Adding a new way to replay rosbags"

Adding a new way to replay rosbags

update travis.yml for noetic and remove find_package(Boost signales)

install slam_gmapping_nodelet

remove signals dep

signals is included in boost > 1.70

The slam_gmapping_replay node is not very easy to debug using RViz.

Users may find convenient this new approach that_

- executes gmapping at maximum speed allowed by the CPU
- all scans are used, none is discarted
- Relevant messages, such as TF and scan, are republished.
- /clock is republished too.

Usage:

rosrun gmapping slam_gmapping scan:=/your_scan
_rosbag:=/path/your/rosbag.bag

since original gmapping source and ROS openslam_gmapping package has been updated to the BSD-3 license, I think we have no reason to use CC for slam_gmapping package

Install nodelet plugin descriptor file as well.

make rostest in CMakeLists optional (ros/rosdistro#3010)

Add missing nodelet dependency to find_package

* Add nodelet implementation.

Add additional nodelet layer to mirror the node
implementation. This allows the Slam GMapping
library to be run as a nodelet instead. This
would allow you to, for example, run it under
the same nodelet manager as the nodelet producing
the /scan output for greater efficiency.

* Remove superfluous semicolons

Removed superfluous semicolons and
mildly clarified info stream output.

* fix comment, change type from double to int

* fix comment, iterations param is not double but int

make sure the laser sent to gmapping is always centered