Partial fix for Boost 1.56 with Visual Studio 2013. More errors remain.

gtsam/base/types.h

@@ -299,6 +299,8 @@ namespace gtsam {
 
 // Define some common g++ functions and macros we use that MSVC does not have
 
+#if (_MSC_VER < 1800)
+
 #include <boost/math/special_functions/fpclassify.hpp>
 namespace std {
   template<typename T> inline int isfinite(T a) {
@@ -309,6 +311,8 @@ namespace std {
     return (int)boost::math::isinf(a); }
 }
 
+#endif
+
 #include <boost/math/constants/constants.hpp>
 #ifndef M_PI
 #define M_PI (boost::math::constants::pi<double>())