FW: Improve Recents (2/2)

- Moved Kill-All option to RB Settings
- Create list preference for different options
- Remove ugly Kill-All button and replace it with image
- Give the user the option to specify location of image (Bottom/Top/Left/Right)
- Add RB Icon for No recents apps
- Move recent items to the middle
- Add header to recent items
- Switch app icons to the right of recent items