Solves a previous unnoticed problem with updating.

When working on bug 3290, there was some troubles with getting the
account id correct. This problem was solved by make a forced update of
the variables in NewAccountWizard.performOk().
Adds the possibility to give an account property a default value
Merge pull request #27 from KlasJoenssson/UpdateFix

Adds the possibility to set a default value