Fix undefined _ASSERT in clamp function for MSVC.

src/include/stratagus.h

@@ -57,6 +57,7 @@
 #pragma warning(disable:4761)               /// Integral size mismatch
 #pragma warning(disable:4786)               /// Truncated to 255 chars
 #include <stdlib.h>
+#include <crtdbg.h>
 #define abort() _ASSERT(0)
 #include <stdio.h>
 #define snprintf _snprintf

src/include/util.h

@@ -180,7 +180,7 @@ extern long isqrt(long num);
 template <typename T>
 void clamp(T* value, T minValue, T maxValue)
 {
-	//Assert(minValue < maxValue);
+	Assert(minValue < maxValue);
 
 	if (*value < minValue) {
 		*value = minValue;