[FIX] account:  the 'Customer taxes' field on the product is readonly when my product doesn't have any variant
Merge pull request #1337 from odoo-dev/saas-5-fix-product-taxes-view-chm

[FIX] account:  the 'Customer taxes' field on the product is readonly when my product doesn't have any variant
[FIX] website_sale: fix error in tracking_last_order which was using the field is_delivery from module delivery
[FIX] ir_attachment: _filestore cache ignore uid

replace ormcache_context by ormcache: use the context in the cache key is useless
set skiparg=3 (default skiparg=2) so the uid is not used in the cache key: the filestore path is the same for all database users
[FIX] stock: backport of rev 0a6d63b
Forward port of branch saas-5 up to eda2f06