Fixing #1134.
Odoo stores values of computed fields at the end of the transaction
only, as such performing a 'read()' to make a data snapshot on the record
created in the current transaction doesn't return the expected result
regarding these fields.
Also as a side-effect 'read()' alters the environment cache and break the
values on the record inducing issues in the whole user
transaction/workflow.
This fix replaces the use of 'read()' to do the data snapshot directly
from the cache of the record (computed values are already there).