New disk selection interface with not BMP

Here there is the new pull request without the bmp. Please, let me know if it is all ok now! Thanks!

New disk selection interface without (hopefully) the BMP

The Configuration Dialog -> Disks tab now has combos to show insert/eject disks, as well as it now the images are automatically swapped if you try to insert on one drive the image connected to the other

(*) Updated based on first review:
- Removed bmp from this pull request (coming later)
- Corrected resource's constants values and deleted unused one
- Initializing variables in CPageDisk constructor