The old-api model._all_columns contains information about model._columns and
inherited columns. This dictionary is missing new-api computed non-stored
fields, and the new field objects provide a more readable api...
This commit contains the following changes:
- adapt several methods of BaseModel to use fields instead of columns and
_all_columns
- copy all semantic-free attributes of related fields from their source
- add attribute 'group_operator' on integer and float fields
- base, base_action_rule, crm, edi, hr, mail, mass_mailing, pad,
payment_acquirer, share, website, website_crm, website_mail: simply use
_fields instead of _all_columns
- base, decimal_precision, website: adapt qweb rendering methods to use fields
instead of columns
f2e4a10e1a