* use Validated/Invalidated instead of Open/Close for Account.
* use Start/Stop instead of Open/Close for Accounting Period.
* update descriptions in workflow states and transitions.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@26116 20353a03-c40f-0410-a6d1-a30d3c3de9de