Changed unit test so it has the same behavior everywhere. Previously, since

the order of function argument evaluation is not defined, the test had slightly
different results on different systems which could cause the tests to falsely
indicate failure.

dlib/test/filtering.cpp

@@ -46,8 +46,10 @@ namespace
             if (rnd.get_random_double() < 0.7 || count < 4)
             {
                 // make a random bump
-                dlib::vector<double,2> pp(rnd.get_random_gaussian()/3,
-                                          rnd.get_random_gaussian()/3);
+                dlib::vector<double,2> pp;
+                pp.x() = rnd.get_random_gaussian()/3;
+                pp.y() = rnd.get_random_gaussian()/3;
+
                 ++count;
                 kf.update(p+pp);
             }