[ADD] new fields.Monetary + updated widgets

Enhance current widget="monetary" client-side feature and
convert it to a first-class type of field, allowing proper
server-side behavior.

- fields: add field.Monetary, similar to fields.Float but
  supporting a `currency_field` attribute instead of the
  decimal_precision attribute.
  `currency_field` indicates the field holding the
  related currency on the same record.
  The symbol of that currency is used when displaying
  the field, and the rounding of the currency is applied
  instead of the usual decimal precision.
- avoids application of a second decimal precision rounding,
  as was the case when the model field was a `fields.float`.
- removes the need for adding explicit boilerplate to each
  view containing a monetary field, i.e.:
    widget="monetary" options="{'currency_field': 'currency_id'}"
- res.currency: add new field decimal_places needed to round
  value at the correct decimal places
- web: cache all currencies, rounding and symbols at
  webclient startup to speedup monetary fields
- new widget monetary for list view + adapt widget monetary
  on form view

Limitations:
- if the currency_field is a related field, the server-side
  application of currency rounding will only work when the
  record already exists, not during creation (to be fixed)
- this field is only supported in the new API

1 files changed, 2 insertions, 0 deletions

diff --git a/addons/web/static/src/js/framework/formats.js b/addons/web/static/src/js/framework/formats.js
index a8dc52bee4a..9efd799a481 100644
--- a/addons/web/static/src/js/framework/formats.js
+++ b/addons/web/static/src/js/framework/formats.js
@@ -46,6 +46,7 @@ function format_value (value, descriptor, value_if_empty) {
         case 'integer':
             return utils.insert_thousand_seps(
                 _.str.sprintf('%d', value));
+        case 'monetary':
         case 'float':
             var digits = descriptor.digits ? descriptor.digits : [69,2];
             digits = typeof digits === "string" ? py.eval(digits) : digits;
@@ -133,6 +134,7 @@ function parse_value (value, descriptor, value_if_empty) {
             if (isNaN(tmp) || tmp % 1)
                 throw new Error(_.str.sprintf(_t("'%s' is not a correct integer"), value));
             return tmp;
+        case 'monetary':
         case 'float':
             tmp = Number(value);
             if (!isNaN(tmp))