Move Point2D utils into own package and add some math operations on P2Ds
Add some javadoc
Remove a duplicate static method
Add circle and line classes for more general collision detection
Add circle-line intersection algorithm
Add test for circle-line intersection algorithm
Add constructors and contains predicate to Line
Add tests for constructors and contains predicate of Line
Add method to find chordal lines for cirles and its test
Make cirelce's chordal method return null if no unique result instead of
throwing random exceptions.
Remove unused import
Add circle-circle-intersection algorithm and its test.