Exemples:
* /sys/fetch_changesets (=> fetches changesets for all active projects)
* /sys/fetch_changeseys?id=foo (=> fetches changesets for project foo only)

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@3107 e93f8b46-1217-0410-a6f0-8f06a7374b81