This imports some of the changes made in the official Debian packaging
repository: https://anonscm.debian.org/cgit/pkg-voip/ring.git

- Don't run containers in interactive mode, which would require a TTY

- Build LRC with Debug symbols

- Build with V=1 to allow parsing logs

- Reorganize dependencies

- Try fetch-all three times before giving up

- Removed ubuntu15.04 references

Tuleap: #858
Change-Id: If0a81b15230a31d120982e113e695443262568e3

This moves the official Debian packaging into ring-project. Jenkins
should now be able to run packaging jobs and publish packages. It
should also make it easy to add a `verify` check on Jenkins to test
packaging patches.

This will make it much easier to work on packaging issues because the
build environment is now reproductible on any machine.

The patch adds Makefile targets to create packages such as:
 - package-all
 - package-<DISTRO>

Builds are all done inside Docker containers and it is possible to
build many at a time with the `package-all` target.

To debug a build, use `package-<DISTRO>-interactive` to obtain a shell
inside a container, ready to launch a build.

Tuleap: #781
Change-Id: Id87a74a6c412ffc5bf82b9562639ce5a9424b06a

This script comes from the jenkins jobs that publishes release tarballs
on https://dl.ring.cx/ring-release/tarballs/. It is best to make it
available in the source so that people can see how we generate our
tarballs and maybe use it for other purposes.

Change-Id: Ie0b302a562e92935ff97661fc85d31cdf20e0cf5
Tuleap: #254