ROS 2 Launch System (#163)

* wip

* more work in progress

* more work done on the calling conventions section

* added context section, still a WIP

* updated event sections

* event filters

* fixup even handler subsection

* typos

* add subsections about the system description (language agnostic)

* Proposal for launching dynamically composable nodes (#206)

* Proposal for dynamically composed nodes

* allow multiple extra_arguments

* Allow node_name and namespace to be empty

* Human readable error message

* Update articles/150_roslaunch.md

Co-Authored-By: sloretz <[email protected]>

* Assign nodes unique ids, but still forbid duplicates

* Update articles/150_roslaunch.md

Co-Authored-By: sloretz <[email protected]>

* Update articles/150_roslaunch.md

Co-Authored-By: sloretz <[email protected]>

* Section to list

* More generic wording about container processes

* namespace -> node_namespace

* _launch/ -> ~/_container/

Signed-off-by: Shane Loretz <[email protected]>

* Propose ROS 2 launch front-end design hints. (#208)

Signed-off-by: Michel Hidalgo <[email protected]>
Signed-off-by: ivanpauno <[email protected]>

* Adds ROS 2 launch XML format design document (#207)

Signed-off-by: Michel Hidalgo <[email protected]>
Signed-off-by: ivanpauno <[email protected]>

* Update ROS launch documentation (frontend documents) (#247)

Signed-off-by: ivanpauno <[email protected]>

* review fixup

Signed-off-by: William Woodall <[email protected]>

* clarify lifecycle transition due to review comment

Signed-off-by: William Woodall <[email protected]>

* provide rationale for shutdown procedure

Signed-off-by: William Woodall <[email protected]>

* Add launch XML substitution for a packages share directory (#254)

* Add launch XML substitution for a packages share directory

Rename find-pkg to find-pkg-prefix.
Add find-pkg-share substitution for the share directory.

Signed-off-by: Jacob Perron <[email protected]>

* remove some old rfc's and general cleanup for first merge

Signed-off-by: William Woodall <[email protected]>