fixing c standard lib includes

include/blah_common.h

@@ -5,6 +5,7 @@
 #include <stddef.h>    // for std::size_t
 #include <stdlib.h>    // for abort
 #include <stdarg.h>    // for string format methods
+#include <stdio.h>     // for vsnprintf
 #include <math.h>      // for standard lib math functions used in blah_calc.h
 
 // Numeric Types

include/blah_string.h

@@ -17,13 +17,13 @@ namespace Blah
 
 		char& operator[](int index)
 		{
-			BLAH_ASSERT(index >= 0 && index < length(), "Index out of range");
+			BLAH_ASSERT(index >= 0 && index < length() + 1, "Index out of range");
 			return s_ptr()[index];
 		}
 
 		const char& operator[](int index) const
 		{
-			BLAH_ASSERT(index >= 0 && index < length(), "Index out of range");
+			BLAH_ASSERT(index >= 0 && index < length() + 1, "Index out of range");
 			return s_ptr()[index];
 		}