[SAC] GEOS git repo created

FYI, I've created a git repositoy for GEOS:

  git://git.osgeo.org/geos # read-only
  https://<osgeo\_user>@git.osgeo.org/git/geos # read-write

For the moment it will cohexist with the SVN repository
to make some tests, then eventually it'll become the official
source for GEOS, replacing the SVN one which may remain in
read-only form to keep all references still alive.

With the occasion I've fixed /var/www/git to be 755 root.root
(previously was 777 root.root) and /osgeo/tools/create_git_repo.sh
to report the correct read-write url.