+ 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);
 

src/Mod/Mesh/Gui/PreCompiled.h

@@ -41,6 +41,7 @@
 #   pragma warning( disable : 4251 )
 #   pragma warning( disable : 4503 )
 #   pragma warning( disable : 4275 )
+#   pragma warning( disable : 4273 )
 #   pragma warning( disable : 4786 )  // specifier longer then 255 chars
 #endif
 

src/Mod/Part/Gui/PreCompiled.h

@@ -39,15 +39,16 @@
 # define NOMINMAX
 #endif
 
-
-#ifdef _PreComp_
 // here get the warnings of too long specifiers disabled (needed for VC6)
 #ifdef _MSC_VER
 # pragma warning( disable : 4251 )
 # pragma warning( disable : 4503 )
 # pragma warning( disable : 4786 )  // specifier longer then 255 chars
+# pragma warning( disable : 4273 )
 #endif
 
+#ifdef _PreComp_
+
 // standard
 #include <iostream>
 //#include <stdio.h>

src/Mod/PartDesign/Gui/ViewProviderAddSub.cpp

@@ -88,7 +88,7 @@ void ViewProviderAddSub::attach(App::DocumentObject* obj) {
     else
         material->diffuseColor = SbColor(1,0,0);
     
-    material->transparency = 0.7;    
+    material->transparency = 0.7f;
     auto* pick = new SoPickStyle();
     pick->style = SoPickStyle::UNPICKABLE;
     

src/Mod/PartDesign/Gui/ViewProviderDatumCS.cpp

@@ -129,7 +129,7 @@ void ViewProviderDatumCoordinateSystem::attach ( App::DocumentObject *obj ) {
 
     getShapeRoot ()->addChild(axisLabelYToZTrans);
     SoRotation *rot = new SoRotation();
-    rot->rotation = SbRotation(SbVec3f(1,1,1), 2*M_PI/3);
+    rot->rotation = SbRotation(SbVec3f(1,1,1), static_cast<float>(2*M_PI/3));
     getShapeRoot ()->addChild(rot);
     t = new SoAsciiText();
     t->string = "Z";

src/Mod/Robot/Gui/PreCompiled.h

@@ -43,6 +43,7 @@
 
 #ifdef _MSC_VER
 #   pragma warning(disable : 4005)
+#   pragma warning(disable : 4273)
 #endif
 
 #ifdef _PreComp_