Refactor for new implementation (#3)

Version 0.2.0 (#2)

* Prepare version 0.2.0 branch

* Updated 1-dimensional examples

* Added 2-dimensional euclidean API

* Added 2-dimensional toroidal API

* Updated README.md

Version 0.1.1 (#1)

* Prepare version 0.1.1 branch

* Update README.md

* Add @return tags for javadocs