+ fix various warnings with VC12

src/Mod/Fem/App/FemConstraint.cpp

@@ -62,9 +62,11 @@
 using namespace Fem;
 
 // maybe in the c++ standard later, older compiler don't have round()
+#if _MSC_VER <= 1700
 double round(double r) {
     return (r > 0.0) ? floor(r + 0.5) : ceil(r - 0.5);
 }
+#endif
 
 PROPERTY_SOURCE(Fem::Constraint, App::DocumentObject);