In a workflow context (for instance, in the invoice workflow),
context is not passed.
Therefore, relying on the 'recompute' key being the context
in order to not recompute the fields does not work with Workflows.
It leads to huge performance issues,
as fields are recomputed recursively (instead of sequentially)
when several records are implied.
For instance, when reconciling several invoices with one payment
(100 invoices with 1 payment for instance),
records of each invoice are recomputed uselessly in each workflow call
(for each "confirm_paid" method done for each invoice).
With a significant number of invoices (100, for instance),
it even leads to a "Maximum recursion depth reached" errror.
closes#4905
c9154e08aa