eliminate all the warnings on win32 and win64

add a new function abssum
fix the bug of test and perf because someone remove non-free module from cmakelist.txt

modules/ocl/src/mssegmentation.cpp

@@ -150,7 +150,7 @@ namespace
     // Implementation
     //
 
-    DjSets DjSets::operator = (const DjSets &obj)
+    DjSets DjSets::operator = (const DjSets &/*obj*/)
     {
         //cout << "Invalid DjSets constructor\n";
         CV_Error(-1, "Invalid DjSets constructor\n");