Support for standardized building of containers

[mfarina1]

Support for using “*-compose build” in place of build.sh for standardized building of the containers.
As a side-effect, this largely enables support for Podman. Conversely, it may also require distribution of additional dependency images to keep compose happy when publishing built containers – using a dummy service is the only way to ensure pre-requisites are built.

[DavidEdell]

This has been implemented in the dsn-devel branch. The compose file now includes 3 builder-* images to allow for correct building of dependencies. These images will always be started with the system, but will, by design, exit immediately upon startup.

See the README file in that branch and #134 for details.