SimMath Version 1.1.0

Incremental improvements and new Grid and GridCell classes.

Full change list:

• Added an alternate AaBBox.setCenter(double, double, double) method.
• Added Matrix3d.addLocal(Matrix3d).
• Added Matrix3d.setSkewSymmetric(Vec3d).
• Modified Matrix3d.set() and Matrix3d.makeIdentity() to return 'this'
  Matrix3d.
• Modified Vec3d.set() to return 'this' Vec3d.
• Added Vec3d.isNaN() which will return true if any of the components
  are NaN.
• Added a Vec3d constructor that takes a JME Vector3f as a reciprocal to
  the existing toVector3f() method.
• Added Grid and GridCell classes for standardizing the partitioning of
  3D space into regularly spaced cells.
• Made several of the classes Serializable: Quatd, Vec3d, Vec3d, Matrix3d,
  Matrix4d, and AaBBox.
• Made Matrix3d, Matrix4d, and AaBBox cloneable.
• Added a Quatd constructor that takes a JME Quaternion as a reciprocal to
  the existing toQuaternion() method.