Settings Exporter - private PR

[rwf-rr]

This is the SettingsExporter, to be added on top of the Settings refactoring openrails#1030.

New Contrib.SettingsExporter command-line executable.

C:\Users\roger\source\repos\rwf-openrails\Program>Contrib.SettingsExporter /help

Usage: Contrib.SettingsExporter <from> <to>
  <from>     Specify the source to load settings from. It may be:
               INI  : use the default INI file OpenRails.ini.
               REG  : use the default registry key SOFTWARE\OpenRails\ORTS.
               path : a specific INI file, relative to the OpenRails main folder. Must end with ".ini".
               key  : a specific registry key, relative to the HKEY_CURRENT_USER key.
  <to>       Specify the destination to save the settings to. Similar to <from>.
  /h, /help  Show this help.

This utility reads the Settings (Options) from one location, and exports them to another location.
It creates a backup of any settings that will be overwritten. Example:
  <installfolder>\OpenRails.ini.bak
  HKEY_CURRENT_USER\SOFTWARE\OpenRails\ORTS-Backup
This utility is intended to:
- Create an INI file that has the same settings as what is in the registry.
  Example: Contrib.SettingsExporter REG INI
- Copy the settings from an INI file back into the registry, so that other installations
  use the same settings.
  Example: Contrib.SettingsExporter INI REG
- Backup the settings, before making temporary changes (and restore afterwards).
  Example: Contrib.SettingsExporter REG SOFTWARE\OpenRails-Saved\ORTS

Exporting from the Registry, when OpenRails.ini already exists.

C:\Users\roger\source\repos\rwf-openrails\Program>Contrib.SettingsExporter REG INI
Info: Loading from SOFTWARE\OpenRails\ORTS.
Info: Successfully loaded settings from HKEY_CURRENT_USER\SOFTWARE\OpenRails\ORTS.
Info: Backed up existing INI file as C:\Users\roger\source\repos\rwf-openrails\Program\OpenRails.ini.bak.
Info: Saving to C:\Users\roger\source\repos\rwf-openrails\Program\OpenRails.ini.
Info: Successfully saved to C:\Users\roger\source\repos\rwf-openrails\Program\OpenRails.ini.

The actual output includes a list of UserSettings names. These are printed by the following code in UserSettings.Save():

            foreach (var property in GetProperties())
                if (property.GetCustomAttributes(typeof(DoNotSaveAttribute), false).Length == 0)
                {
                    Console.WriteLine(property.Name, property.PropertyType);
                    Save(property.Name, property.PropertyType);
                }

I am not sure why that Console.WriteLine is there. The other settings classes don't have it.