fix project deletion

git-svn-id: https://svn.apache.org/repos/asf/archiva/trunk@1579883 13f79535-47bb-0310-9956-ffa450edef68
fix retrieving ArtifactMetadata with null date

git-svn-id: https://svn.apache.org/repos/asf/archiva/trunk@1579884 13f79535-47bb-0310-9956-ffa450edef68
NPE check!

git-svn-id: https://svn.apache.org/repos/asf/archiva/trunk@1579885 13f79535-47bb-0310-9956-ffa450edef68
fix retrieving a project

git-svn-id: https://svn.apache.org/repos/asf/archiva/trunk@1579886 13f79535-47bb-0310-9956-ffa450edef68