changes.md

• 2019-11-04: comma key is now ,, period key is now .
• 2018-08-28: LampObject and LampData is now LightObject and LightData
• 2018-08-28: Use new Vec4(0,0,1) (or Vec4.zAxis()) instead of Vec4.up()
• 2018-08-28: Vec4.lerp is no longer static, use var v = new Vec4(); v.lerp(from, to, s)
• 2018-08-21: Vec4.lerp(to, from, s) is now Vec4.lerp(from, to, s)
• 2017-12-10: Use iron.math.Vec4.distance() instead of iron.math.Vec4.distance3d().