[IMP] [REF] crm: WIP and first attempt to remove state field.

[IMP] [REF] crm: WIP and first attempt to remove state field.

crm.case.section: removed state field
crm.lead: code now use probability and on_change to fetch stages related to
Won and Lost. Improved stage management. Improved a bit the demo data.

mail: improved message_track to use browse_record instead of read result. This allows
to avoid having to track fields to be able to use them in the subtype condition.

bzr revid: tde@openerp.com-20130610142927-tyxxklojv2wxw44g