Removed unused and wrong dot product function (correct dot product is x1*x2+y1*y2)
Fix: The speed change from a flap shouldn't depend on physics time step size
Let's make some use of the dist function if it's there already
Fix inconsistent physics rate
Added linear interpolation for birds and particles
Improved ground collision: Actually places you on the ground now
Move flap force application to the beginning of the main loop to reduce input latency
Added missing semicolon
Add nearest-neighbor scaling support for Internet Explorer
Use high-resolution timestamp provided in requestAnimationFrame callback
Merge pull request #3 from Medo42/LinearInterp

Linear interpolation plus minor improvements