COCOON-2330 Release separate source and dependencies packages 
Remove all old legal/*.license.txt stuff
Modify build-dist.xml to reflect the new location of licensing information

git-svn-id: https://svn.apache.org/repos/asf/cocoon/branches/BRANCH_2_1_X@1444938 13f79535-47bb-0310-9956-ffa450edef68