Include file error in Visual Studio 2008 and lower.

Visual Studio 2008 wont compile the 0.5.0 release since it dosen't have <stdint.h> (included in amqp.h line 162).
To fix this, the stdint.h that comes with the 0.5.0 release can be used (librabbitmq/win32/msinttypes/stdint.h)

using the _MSC_VER define the right file can be included.

#if (defined(_MSC_VER) && _MSC_VER<=1500)
	#include "win32/msinttypes/stdint.h"
#else
	#include <stdint.h>
#endif