It's possible to control which Skin Layer should be changed, if new Skin (in case provided by this bt5)
should be installed and if reordering based on skin folder priority should be applied.
Extend test to cover this new features.



git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@24739 20353a03-c40f-0410-a6d1-a30d3c3de9de