Rework FileSaveClick so it never calls FileSaveAsClick.
FileSaveClick: fixed name/location of configuration means we'll always be using standard serializer.
FileOpen doesn't need to prepopulate file name -- remove it.
ClientSettingsManager: FileName and FilterIndex are now virtually unused -- remove them.
CheckForConfigurationChanges is obsolete. Convert it to CheckForClients.

This is so user doesn't accidently clear/overwrite his client list
when creating  new configuration or importing configuration.