* This commit prevents developers from doing mistakes like:
Point p1, p2, p4;
if (p1 + p2 = p4) { // Bang! We actually wanted to compare
// the result of two points: (p1 + p2 == p4).
// do something.
}
See, e.g., http://www.gotw.ca/gotw/006.htm for details.
* Add more test cases according to this change.
* Move a helper function to compare floating point numbers
to Util.h.
