Restore skin selection after each activity invocation, to make sure activity mechanism can work (it relies on skins to reach ZSQLMethods for activity book-keeping).
Also, solves problems where activities invoked after an activity which called changeSkin would get an unexpected skin selection.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@24897 20353a03-c40f-0410-a6d1-a30d3c3de9de