upgrade skin to at least 2.0

This is a chicken egg problem. The skin would need to be maintained
outside the project which uses it. Otherwise it's not possible
to do a proper release without having to change things manually


git-svn-id: https://svn.apache.org/repos/asf/geronimo/genesis/trunk@1454050 13f79535-47bb-0310-9956-ffa450edef68