Updated index page with information about version 2.0.
Updated index page with information about version 2.0.

The text had to be adapted as the final version is now available. The
current wording was only talking about alpha and beta versions.

git-svn-id: 0d31da9e303333003508381311333cf78a25d41b@1735779 13f79535-47bb-0310-9956-ffa450edef68

apache/commons-configuration,apache/commons-configuration,apache/commons-configuration