Changing some folders names and creating XML for `compositeAtrifacts`
and `compositeContent`.
In erclt.py:
Artifacts are released under 'releases/milestones/<version>'.
XML is updated at 'releases/milestones/<version>',
    created at 'releases/milestones/<version>/ldt'.
Products and update site artifacs now have their own command line
option.

In erclt.py:
Products are copied under 'product/current-milestones'.
If not provided in command line, they are fetched from continuous
integration.
Polishing details:
 * Products are archived under archive.eclipse.org
 * Directory which contains last milestone has right permissions
 * Statistics are activated only for ldt feature
Restoring hard Python 2.6 requirement.
Adding timestamp and titles to compositeArtifacts.xml and
compositeContent.xml
Fixing folder rights.
Refactoring the way path are handled.
Update README.md
being refactoring
add release and milestone action
plug new action with CLI
fix problem
add set permission for products
Adding stats on remote feature