Previously, you may have gotten values like 639x480 (4:3) or 853x480 (16:9).
These are due to rounding errors caused by lrintf; ceilf does what we really want.
[RageDisplay.cpp] modified screenshot function
[ScreenDimensions] modified SCREEN_WIDTH and SCREEN_HEIGHT algorithms (no longer do you need to SCREEN_WIDTH+1 for 16:9 support)
[StepMania.cpp] modified windowed mode width calculation
AJ Kelly