This packages RxCpp (version 4.1.0) as a ROS 1 Catkin package, allowing it to be built as part of a Catkin workspace.

No changes have been made to the sources, they have only been packaged.

Dependents should add a build_depend (and if needed, a build_export_depend) on the rxcpp_vendor package.

Headers are installed into <prefix>/include/rxcpp (not rxcpp_vendor), so the normal include paths can be used in source files.

No future changes to this package are expected, other than perhaps tracking upstream if/when new RxCpp releases are made.

A Bloom 3rd party release may be considered if that is considered less maintenance or deemed more compatible.