Remove user and administrator account creation from MigrationConfiguration

[makigjuro]

Now development user and administrator account are created in MigrationConfiguration.cs. We need to remove account creation from this file.

At the very least leave only service users and a single administrator account (Master administrator) in this file.
Also, we need to reset passwords for ALL the users and administrator accounts mentioned in the migrations file and make sure that new password never appear in the Fr8Config repository files. If necessary, move them to the Settings.config files located in the Fr8Config repository.
A better route would be to create a simple setup wizard (a la Wordpress) which would show up at the first run and allow User to create a master administrative account. Later we could use this wizard to simplify other kinds of configuration (e.g. email server settings).