BUILDR-689 - Define assets task before the project is defined to avoid "undefined method `project='" if the project attempts to generate into the same directory.

git-svn-id: https://svn.apache.org/repos/asf/buildr/trunk@1534852 13f79535-47bb-0310-9956-ffa450edef68
BUILDR-689 - Ensure that war file includes generated assets rather than the "source" assets that may have  been filtered.

git-svn-id: https://svn.apache.org/repos/asf/buildr/trunk@1534859 13f79535-47bb-0310-9956-ffa450edef68