1. Bugfix: Some configs were affected by presets although they shouldn't have (e.g. MultitapEnabled and few more).
2. Bugfix: GUI: moving the presets slider was forcing unaffected values to last applied settings (would override settings changes which took place at the GUI while presets are enabled, e.g. most GSWindow options).
3. Better code resilience for future SysConfigDialog panels which might not be affected by presets.
4. Removed unused code and improved comments.
git-svn-id: http://pcsx2.googlecode.com/svn/trunk@4237 96395faa-99c1-11dd-bbfe-3dabce05a288