[transaction] handle ``mode`` default value in Transaction
The transaction mode is now explicitly passed at creation time and always read
from the Transaction object.
Note that there is a slight behavior change. The transaction mode is now set at
the creation of the transaction. Changes made to the default value have no
longer any effect on existing transaction.
[system]
db-driver = postgres
db-host = localhost
db-port = 5433
adapter = native
db-name = cw_fti_test
db-encoding = UTF-8
db-user = syt
db-password = syt
[admin]
login = admin
password = gingkow