Tweak benchmark to display frame-to-frame time as well
Fix for loud audio in Flash shim

If we hit 1.0 we got crackly audio with the new hex stuff.
Clamping values to fit 16-bit integers.
Show last 5 seconds of benchmark data instead of all of it

easier to see what's going on continuously
Merge pull request #52 from maikmerten/master

do sign extension via arithmetic shift instead of branching, assemble ni...
Drop Flash audio precision to 15-bit to skip clamping for headroom

Gets audio working ok with the loud 'Cassini Reveals New Ring Quirks' video
while skipping the extra branches for the clamp.