[IMP] pocurement, stock, purchase, sale_stock, stock_account: misc changes in...

[IMP] pocurement, stock, purchase, sale_stock, stock_account: misc changes in usabilty, code refactoring and new option on procurement group propagation.
1) form view of procurement.order and procurement.rule reviewed
2) added buttons on procurement.order to jump on other procurements or pickings of same procurement.group
3) tracked some fields on procurement.order
4) used the short name of warehouse for the rule names
5) added a new choice for the procurement.group propagation in order to allow having only one reception picking for several po lines grouped in the same PO but belonging to different procurement.group at first
6) some code refactored for easiness, modularity, clarity and other obvious reasons

bzr revid: qdp-launchpad@openerp.com-20131107112053-knracfslqkfitg8b