Implement support for default options?

[FrodeSolheim]

Background: FS-UAE / FS-UAE Launcher options are currently categorized as "configuration options" and "settings". The former is per-configuration options, and the latter is global preferences, applied to all configurations. "floppy_drive_0" is an example of the former, and "fullscreen" of the latter.

The current behavior is to disallow the user from entering configuration options in advanced settings - that is, the user can write them there, but they will be ignored. There are a couple of reasons for this:

• The config UI has no mechanism yet to show that an option value is inherited from global settings.
• The net play synchronization code synchronizes configuration options, but not settings.

The user can override settings in configuration files, but not vice versa because of the above points. Another reason is that if you for example could change "accuracy" globally, when you get a config file from another person, it will not be clear that your global settings will apply (if the config file does not specify accuracy itself), and this could cause confusion since the config file could work for one person and not for others (depending on inherited configuration values).

So a prerequisites for allowing the user to change (default) configuration options globally is:

• The config UI must be display the overridden default for configuration controls.
• The config UI should warn the user when configuration options (affecting the emulation) use overridden default global values (created config file may not be portable, and loaded configs may not work as intended).

[FrodeSolheim]

This is basically already implemented.