Cleanup and unify makedist scripts

We have a lot of different makedist scripts for the different FEniCS packages. They are all adaptions of some common script and do slightly similar things. These scripts are very fragile and often break between releases. It would be good to cleanup these scripts and reuse as much code as possible.

Some suggestions:

1. All packages have versions of the for x.y.z (three numbers).

2. Create release tarballs in release/foo-x.y.z.tar.gz

3. Put makedist script in release directory and rename so the command to run is

  release/make

4. When an installation is necessary, for example to run tests before release, then make the installation under

  release/build