Enable Custom Fields in Naming Series

[raveslave]

Extend the "Autoname rules" to allow retrieve and insert a value from a document / custom field.

Background:

Some companies prefers to make use of "short-codes" for suppliers, i.e. WN for company "Web Notes" that later can be used in naming series for quick identication.

Example:

• A custom field "Vendor ID" is created under Document: Supplier.
• Then under Naming Series, we should allow something like
  • PO-.YY.MM.-.{vendor_id}.-.#####
  • Resulting in "PO-1503-WN-00001"

[superlack]

I am hoping this becomes something out of the developer mode spectrum.