[IMP]: Reduce memory usage when importing inventories with many stock moves

Fixes https://bugs.launchpad.net/ocb-addons/+bug/1312045 : "we're having problems importing an inventory for a location that contains >630000 Stock Moves.
The problem seems to lie in the python loop based on the browse() of the Stock Moves: it preloads too much data and pushes the OS to an out-of-memory condition (which Linux responds to by killing the openerp server)."
This patch solve this bug by splitting stock moves lines ids on separated list of 10.000 lines