Allow to save profile without account and fill it automatically

[user9931]

Will be nice to have an option to save profile without account name (and email) and password when UseAccountPassword is enabled. Its retrived anyway (if those fields are empty) with click on "Get IMAP/POP3 account settings". Yes, its possible to clean those fields in gui (except password), but for some reason those fields and and are saving anyway. Its possible to edit in text editor later

And on profile loading, when and and are empty and UseAccountPassword is set to true it would be nice to automatically "Get IMAP/POP3 account settings" on profile load

[aluxnimm]

Useful for passwords only. We don't need to store password and salt when UseAccountPassword is enabled, will be fixed in next release. But other values need to be stored since they can be changed after getting them from imap/pop3 account settings.