only use alpha channel if it exists
improve patch according to reviewer's suggestion
POS is loading all partners, not only customers

Hi,

Adding domain to res.partner model, so POS only loads "customers"
[FIX] product: creation of reference uom

Set a default value for factor when creating a new uom.
Could not create a new UoM with type reference (if creates a reference uom, no need to pass a factor).

Change the readonly filter to (type = bigger) to make the field writable for reference uom.
This is needed to force the reset of the factor when switching of type (onchange_type).
As the field was readonly, kept the old value for factor.
[FIX] project_timesheet: date of created analytic line not in user tz

When the user was in timezone UTC + 1, and added a project.task.work which created an analytic entry line (timsheet activity), if the datetime was set to 11/25 00:00:00, the date on the analytic line was set to 11/24, because this was the truncated stored value(UTC Time), which was 11/24 23:00:00
[FIX] account: prevent invoice line duplication on partner duplication

If a company contact (a partner with a company set as parent) had invoices, and the company of this contact was duplicated, all the invoices lines were duplicated,  on the original invoice moreover (new lines were added on existing invoices)
[FIX] mrp_operation: missing context

It is present in mrp declaration but was not in mrp_production which was problematic if another module inherit as well from action_produce_end.
[FIX] payment: docstring typo

closes #3557
[FIX] doc: typo in themes document

closes #3874
[FIX] account: bank statement reconciliation widget: disable buttons which trigger RPC calls until done
[FIX] marketing_campaign: typo in manifest
[FIX] website_reseller: Navigation Broken for Partner List on Website issue#3522
[FIX] website_sale: Discussion not working on product; issue: #3495
[FIX] account: bank statement reconciliation widget: correct multicurrency display
[FIX] mrp: duplicated xmlid for ir.model.access
[FIX] l10n_br: remove reference to old base.group_extended group

Fixes #3879
[IMP] account: bank statement reconciliation widget: allow to filter move lines on due date
[FIX] doc: remove a word that does not make sense

closes #3594
[FIX] sale_service: typo in string Thick -> Tick
[IMP] website_sale: performance on category page

public_categ_ids field was moved to product.template object