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.
Hm... seems strange you'd have to access `flixel.system.macro.FlxMacroUtils` for public API in `FlxAngle`.

The only other solution if putting the macro in `FlxAngle` and have `#if macro` conditionals?