[lua] fix and beautify lua.Math extern

(docs taken from https://www.lua.org/manual/5.1/manual.html#5.6)

std/lua/Math.hx

@@ -1,41 +1,152 @@
 package lua;
 
+import haxe.extern.Rest;
+
+/**
+	Mathematical Functions
+**/
 @:native("_G.math")
 extern class Math {
-	public static var pi   : Float;
-	public static var huge : Float;
-	public static var NaN  : Float;
-
-	public static function abs  (i : Float) : Float;
-	public static function ceil (i : Float) : Int;
-	public static function floor(i : Float) : Int;
-
-	public static function acos (i : Float) : Float;
-	public static function asin (i : Float) : Float;
-	public static function atan (i : Float) : Float;
-	public static function atan2(i : Float, j : Float) : Float;
-	public static function cos  (i : Float) : Float;
-	public static function cosh (i : Float) : Float;
-	public static function sin  (i : Float) : Float;
-	public static function sinh (i : Float) : Float;
-	public static function tan  (i : Float) : Float;
-	public static function tanh (i : Float) : Float;
-	public static function rad  (i : Float) : Float;
-
-	public static function modf (i : Float) : Float;
-	public static function fmod (i : Float) : Float;
-
-	public static function pow  (i : Float, j : Float) : Float;
-	public static function sqrt (i : Float) : Float;
-	public static function exp  (i : Float) : Float;
-	public static function frexp(i : Float) : Float;
-	public static function ldexp(i : Float) : Float;
-
-	public static function log  (i : Float) : Float;
-	public static function log10(i : Float) : Float;
-
-	public static function max  (i : Float, j :Float) : Float;
-	public static function min  (i : Float, j :Float) : Float;
+	/**
+		The value of pi.
+	**/
+	static var pi(default,never) : Float;
+
+	/**
+		The value HUGE_VAL, a value larger than or equal to any other numerical value.
+	**/
+	static var huge(default,never) : Float;
+
+	/**
+		Returns the absolute value of x.
+	**/
+	static function abs  (x : Float) : Float;
+
+	/**
+		Returns the smallest integer larger than or equal to x.
+	**/
+	static function ceil (x : Float) : Int;
+
+	/**
+		Returns the largest integer smaller than or equal to x.
+	**/
+	static function floor(x : Float) : Int;
+
+	/**
+		Returns the arc cosine of x (in radians).
+	**/
+	static function acos (x : Float) : Float;
+
+	/**
+		Returns the arc sine of x (in radians).
+	**/
+	static function asin (x : Float) : Float;
+
+	/**
+		Returns the arc tangent of x (in radians).
+	**/
+	static function atan (x : Float) : Float;
+
+	/**
+		Returns the arc tangent of y/x (in radians), but uses the signs of both parameters to find the quadrant of the result.
+		(It also handles correctly the case of x being zero.)
+	**/
+	static function atan2(y : Float, x : Float) : Float;
+
+	/**
+		Returns the cosine of x (assumed to be in radians).
+	**/
+	static function cos  (x : Float) : Float;
+
+	/**
+		Returns the hyperbolic cosine of x.
+	**/
+	static function cosh (x : Float) : Float;
+
+	/**
+		Returns the sine of x (assumed to be in radians).
+	**/
+	static function sin  (x : Float) : Float;
+
+	/**
+		Returns the hyperbolic sine of x.
+	**/
+	static function sinh (x : Float) : Float;
+
+	/**
+		Returns the tangent of x (assumed to be in radians)
+	**/
+	static function tan  (x : Float) : Float;
+
+	/**
+		Returns the hyperbolic tangent of x.
+	**/
+	static function tanh (x : Float) : Float;
+
+	/**
+		Returns the angle x (given in degrees) in radians.
+	**/
+	static function rad  (x : Float) : Float;
+
+	/**
+		Returns two numbers, the integral part of x and the fractional part of x.
+	**/
+	static function modf (x : Float) : Float;
+
+	/**
+		Returns the remainder of the division of x by y that rounds the quotient towards zero.
+	**/
+	static function fmod (x : Float) : Float;
+
+	/**
+		Returns y-th power of x.
+	**/
+	static function pow  (x : Float, y : Float) : Float;
+
+	/**
+		Returns the square root of x.
+	**/
+	static function sqrt (x : Float) : Float;
+
+	/**
+		Returns the value e^x.
+	**/
+	static function exp  (x : Float) : Float;
+
+	/**
+		Returns m and e such that x = m2^e, e is an integer and the absolute value of m is in the range [0.5, 1) (or zero when x is zero).
+	**/
+	static function frexp(x : Float) : MathFrexpResult;
+
+	/**
+		Returns m2^e (e should be an integer).
+	**/
+	static function ldexp(m : Float, e : Int) : Float;
+
+	/**
+		Returns the natural logarithm of x.
+	**/
+	static function log  (x : Float) : Float;
+
+	/**
+		Returns the base-10 logarithm of x.
+	**/
+	static function log10(x : Float) : Float;
+
+	/**
+		Returns the maximum value among its arguments.
+	**/
+	static function max  (x : Float, numbers : Rest<Float>) : Float;
+
+	/**
+		Returns the minimum value among its arguments.
+	**/
+	static function min  (x : Float, numbers : Rest<Float>) : Float;
+
+	/**
+		Returns the angle x (given in radians) in degrees.
+	**/
+	static function deg  (x : Float) : Float;
 
 	/**
 		This function is an interface to the simple pseudo-random generator function rand provided by ANSI C.
@@ -45,11 +156,18 @@ extern class Math {
 		When called with an integer number `m`, returns a uniform pseudo-random integer in the range [1, m].
 		When called with two integer numbers `m` and `n`, returns a uniform pseudo-random integer in the range [m, n].
 	**/
-	public static function random(?m:Float, ?n:Float) : Float;
+	static function random(?m:Float, ?n:Float) : Float;
 
 	/**
 		Sets `x` as the "seed" for the pseudo-random generator: equal seeds produce equal sequences of numbers.
 	**/
-	public static function randomseed(x : Float) : Float;
+	static function randomseed(x : Float) : Float;
 }
 
+/**
+	The return value of `Math.frexp`.
+**/
+@:multiReturn extern class MathFrexpResult {
+	var m:Float;
+	var e:Int;
+}