The "public" branch correspond to developpement for the distributed
version of the software.

To prepare a new release (replace the version appropriately):

* create a new "release" branch from the "public" branch:

  git checkout -b release-1.0.1 public

* edit "Makefile" to change version number (macro RELEASE_VERSION),
  and make any other suitable changes:

  emacs Makefile

* commit the changes (after checking everything is in order):

  git status
  git commit -a -m 'Bumped version number to 1.0.1'

* go to the "master" branch which is only used for releases (see
  http://nvie.com/posts/a-successful-git-branching-model/), merge the
  changes and add a tag:

  git checkout master
  git merge --no-ff release-1.0.1
  git tag -a '1.0.1' -m 'Public version 1.0.1 released.'
  make release

* delete the release branch which is no longer needed:

  git branch -d release-1.0.1
