Use source_trade to specify who will work on a project (it should probably be removed afterall since projects are only reporting structures). Use of reference instead of ID everywhere in requirements. SImplify columns in milestone lists. Added requirement to order matrix generation for requirement coverage. Make requirement report show description only if it exists.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@15771 20353a03-c40f-0410-a6d1-a30d3c3de9de