Add issue management
Make the "create-site" profile work

- verify phase:
  - clone this local git repository into ${site.deploy.directory} and
checkout the gh-pages branch
  - create the maven site at its default location
        
  - install phase: deploy the maven site to ${site.deploy.directory}
      
  - deploy phase:
    - add all changed file to the Git index
    - commit the changes and push them back into this local git
repository