mrp_operations Module Introduction

This module adds state, date_start,date_stop and delay in production order operation lines (in the "Workcenters" tab)
State: draft, confirm, done, cancel
When finishing/confirming,canceling production orders set all state lines to the according state.
Create menus:
Production Management > All Operations
Production Management > All Operations >Production Orders to Do (State=Confirm)
Production Management > All Operations >Waiting Production Orders (state=Draft)
Which is a view on "Workcenters" lines in production order,editable tree

Add buttons in the form view of production order under workcenter tab:
* start (set state to confirm), set date_start
* done (set state to done), set date_stop
* set to draft (set state to draft)
* cancel set state to cancel

When the production order becomes "ready to produce", operations must become 'confirmed'. When the production order is done, all operations must become done.

The field delay is the delay(stop date - start date).
So that we can compare the theoretic delay and real delay.