[FIX] mrp: remove sequence data

Warehouse's routes, locations, picking types and
sequences are now generated on create or with a post
init hook for exisiting warehouses before module installation.

Before the init hook, warehouses created before mrp module installation
do not have a specific sequence number for manufacturing and they
shared the same sequence production created in data.

addons/mrp/data/mrp_data.xml

@@ -2,15 +2,6 @@
 <odoo>
     <data noupdate="1">
 
-        <record id="sequence_mrp_prod" model="ir.sequence">
-            <field name="name">Production order</field>
-            <field name="code">mrp.production</field>
-            <field name="prefix">MO/</field>
-            <field name="padding">5</field>
-            <field name="number_next">1</field>
-            <field name="number_increment">1</field>
-        </record>
-
         <record id="sequence_mrp_route" model="ir.sequence">
             <field name="name">Routing</field>
             <field name="code">mrp.routing</field>

addons/mrp/models/mrp_production.py

@@ -340,7 +340,7 @@ class MrpProduction(models.Model):
         self.location_dest_id = self.picking_type_id.default_location_dest_id.id or location.id
 
     @api.multi
-    def write (self, vals):
+    def write(self, vals):
         res = super(MrpProduction, self).write(vals)
         if 'date_planned_start' in vals:
             moves = (self.mapped('move_raw_ids') + self.mapped('move_finished_ids')).filtered(
@@ -353,8 +353,10 @@ class MrpProduction(models.Model):
     @api.model
     def create(self, values):
         if not values.get('name', False) or values['name'] == _('New'):
-            if values.get('picking_type_id'):
-                values['name'] = self.env['stock.picking.type'].browse(values['picking_type_id']).sequence_id.next_by_id()
+            picking_type_id = values.get('picking_type_id') or self._get_default_picking_type()
+            picking_type_id = self.env['stock.picking.type'].browse(picking_type_id)
+            if picking_type_id:
+                values['name'] = picking_type_id.sequence_id.next_by_id()
             else:
                 values['name'] = self.env['ir.sequence'].next_by_code('mrp.production') or _('New')
         if not values.get('procurement_group_id'):