Pre-release last minute change: moved the WORLD constant from DefaultExtent to the Extents static utility class.
This was planned but we forgot to apply that change before the tag. We apply that change before the release in
order to avoid breaking public API after the release.


git-svn-id: https://svn.apache.org/repos/asf/sis/branches/0.3@1507233 13f79535-47bb-0310-9956-ffa450edef68