Patch by Kenneth Riddile: disable MSVC warnings, reenable them outside

of Eigen, and add a MSVC-friendly path in StaticAssert.

Eigen/Array

@@ -3,6 +3,8 @@
 
 #include "Core"
 
+#include "src/Core/util/DisableMSVCWarnings.h"
+
 namespace Eigen {
 
 /** \defgroup Array Array module
@@ -32,4 +34,6 @@ namespace Eigen {
 
 } // namespace Eigen
 
+#include "src/Core/util/EnableMSVCWarnings.h"
+
 #endif // EIGEN_ARRAY_MODULE_H