Fix sinCosGenerator

A cos and sin tables are generated by default with an amplitude of 360 degrees.

If you need, you can easily generate your own values using sinCosGenerator like this.

```haxe
FlxAngle.sincos = FlxMacroUtil.sinCosGenerator(360, 1, 1, 1);
var cosine = FlxAngle.cosTable[angle];
var sine = FlxAngle.sinTable[angle];
```

Note that sinCosGenerator is a macro, so you have to give him constant values.
Could we turn this into an internal class instead of a typedef? That way, the data can be properly typed on native targets.