[FIX] procurement: magic bypass transition was incomplete and preventing pulled flows...

[FIX] procurement: magic bypass transition was incomplete and preventing pulled flows from working

The procurement workflow has a magic `bypass` transition
that acts as a fallback for MTO procurements in case the
necessary modules are not (yet) installed. For example
it will consider a MTO+Buy procurement directly satisfied
if the Purchase module is not yet installed.
However this bypass transition did not properly take
"internal pulled flows" into account, which are added
by the `stock_location` module as a third kind of procurement
type. In this case the bypass would match and never
give stock_location the chance to run.
In order to be consistent with the other procurement
methods, the bypass transition needs to be adapted.

Also updated the check_move() method to make it more
explicit rather than a side-effect.

bzr revid: odo@openerp.com-20131112151747-da67h4yavhz3k29c