[Mono] Improvements for Mathf
Changes:
- Added Tau, Inf, NaN - constants from GDscript,
- Added Rt2 - Square root of 2
- Added E constant(for compatibility with System.Math class)
- Added InverseLerp, IsInf, IsNaN
- Changed "val" to "value" in parameter names, yes value is keyword but its fine and no problem to use it(same as "from" which also a keyword and already existed in some functions)
- Added int versions of Abs, Clamp and Sign
- Clamp looks much simpler now(single line of code)
- Added CeilToInt, FloorToInt
- Renamed PI to Pi for compatibility with PascalCase
- Changed Wrap for float to more compact version(thanks @aaronfranke)
- Maked Mathf a partial class and placed all extensions and new constants to new MathfEx.cs