Initial commit of rma and rma_sale for Odoo 11.0

Big changes to tests (because of the ways stock has changed) and allow activities to be set on RMAs.  Other refactors to reduce code duplication between picking and so returns.

rma/models/stock_picking.py

@@ -0,0 +1,13 @@
+from odoo import api, models, _
+from odoo.exceptions import UserError
+
+
+class StockPicking(models.Model):
+    _inherit = 'stock.picking'
+
+    @api.multi
+    def send_to_shipper(self):
+        res = False
+        for pick in self.filtered(lambda p: not p.carrier_tracking_ref):
+            res = super(StockPicking, pick).send_to_shipper()
+        return res