[REF] ir_qweb: optimize assets compilation in debug mode
[REF] ir_qweb: optimize assets compilation in debug mode

Mainly by moving the authority to handle the ir.attachments records
for Less and SassStylesheetAsset from the asset to the bundle.

We introduce a method `is_css_preprocessed` that will check if the
less/sass assets contained in a bundle already have ir.attachments
records. On top of that, it'll check if these existing records
need to be invalidated by comparing the last modified date of the
file and the __last_updated field on the record. If it is the case,
we chose to unlink all the less/sass attachments from the same
bundle.

stephen144/odoo,stephen144/odoo,laslabs/odoo,ygol/odoo,sysadminmatmoz/OCB,dfang/odoo,hip-odoo/odoo,Elico-Corp/odoo_OCB,storm-computers/odoo,hip-odoo/odoo,sysadminmatmoz/OCB,ygol/odoo,laslabs/odoo,Elico-Corp/odoo_OCB,ygol/odoo,dfang/odoo,bplancher/odoo,sysadminmatmoz/OCB,Elico-Corp/odoo_OCB,stephen144/odoo,microcom/odoo,bplancher/odoo,microcom/odoo,microcom/odoo,microcom/odoo,laslabs/odoo,storm-computers/odoo,Elico-Corp/odoo_OCB,hip-odoo/odoo,hip-odoo/odoo,storm-computers/odoo,ygol/odoo,microcom/odoo,dfang/odoo,Elico-Corp/odoo_OCB,bplancher/odoo,dfang/odoo,bplancher/odoo,bplancher/odoo,dfang/odoo,hip-odoo/odoo,storm-computers/odoo,microcom/odoo,sysadminmatmoz/OCB,stephen144/odoo,ygol/odoo,hip-odoo/odoo,dfang/odoo,laslabs/odoo,stephen144/odoo,storm-computers/odoo,stephen144/odoo,ygol/odoo,sysadminmatmoz/OCB,laslabs/odoo,storm-computers/odoo,ygol/odoo,Elico-Corp/odoo_OCB,bplancher/odoo,sysadminmatmoz/OCB,sysadminmatmoz/OCB,laslabs/odoo