Thorwin Math 1.5.0

I've just released Thorwin Math 1.5.0. This version contains some internal refactoring (not exposed in API) and changes to the build environment:

• Matrix2x2, Matrix3x3, Matrix4x4 are no longer subclasses.
• Vector2D, Vector3D, Vector4D are no longer subclasses.
• Affine2D, Affine3D are no longer subclasses.
• Replaced ANT with Gradle for building
• Artefacts are now available on Bintray

Removing class hierarchy for various classes is in preparation of expected value-type support in Java 10.