Fixed compilation on Visual Studio 2010 and 2012 (issue #107)

src/Arduino/Print.cpp

@@ -17,6 +17,13 @@
 #pragma GCC diagnostic ignored "-Wfloat-conversion"
 #endif
 
+// Visual Studo 2012 didn't have isnan, nor isinf
+#if defined(_MSC_VER) && _MSC_VER <= 1700
+#include <float.h>
+#define isnan(x) _isnan(x)
+#define isinf(x) (!_finite(x))
+#endif
+
 size_t Print::print(const char s[]) {
   size_t n = 0;
   while (*s) {