Sand Oasis Visual Enhancements

[merlang7]

a visual overhaul of Sand Oasis acts 1 and 3:

• saturates the ambient light to emulate the vibrant Wii shadows
• adds the ability to change Sonic's (and other objects') lighting with greater control, separate from the environment
• adds fog
• improves performance in interiors by removing unnecessary shadow calculations
• adds light cards to exits to mimic a similar effect on Wii
• adds glow
• changes Sonic's material shader to better support the changed lighting