[FIX] stock: fix the problem picking is go in available state.
[FIX] stock: only trigger downstream move processing if all upstream moves are done + revert incorrect patch

The previous patch was incorrect because it was removing the
link between the moves, causing an interruption in the
product traceability
[MERGE] OPW 577110: stock.move: only auto-validate next move if there are no other pending upstream moves

Backport of 7.0 fix at revision 8023 fp@tinyerp.com-20121113085628-a20qtouxxw7gh98b