MRI-Binding: Font: Add get/set_default_out_color binding
SoundEmitter: Show filename that caused the SDL_Sound error
Graphics: Fix resize_screen
TilemapVX: Deal correctly with Graphics.resize_screen
Graphics: Fadein/out should interpolate from current brightness
MRI: WindowVX: Bind RGSS2 constructor (same as RGSS1)
SharedState: Fix asset path priority (rgssad -> "." -> RTPs)