Update recent game list and remove redundant recent games in list.

The following updates are included:
1. Recreate a proper ini file in Config::Save(). 
Aim at avoid leaving old config items in ini file to yield wired behaviors, such as the redundant in the recent game list etc. 
2. Remove the redundant of the recent games when loading ini file.
3. Update the recent game list screen when the "Clear recent game list" menu is checked.

To the 3rd one, it works but maybe someone could suggest me a better method.