Fix build under VS2012 (i.e. MSC_VER = 1700)

cstool.c currently imports inttypes.h, which breaks
building on older Visual Studio versions (I've been
testing 2012). This commit removes the explicit include
of inttypes.h, which is already handled in platform.h
(which is included by capstone.h). A define for the
function strtoull (used by cstool) has also been added
to platform.h for the case where MSC_VER <= 1700.

I don't know what effect this will have on OS X builds
as I'm unable to test on that platform.

Also, cstool.c doesn't need to include stdio.h
because it's already included by capstone.h.
diff --git a/cstool/cstool.c b/cstool/cstool.c
index e832fde..677edaa 100644
--- a/cstool/cstool.c
+++ b/cstool/cstool.c
@@ -1,6 +1,4 @@
 /* Tang Yuhang <tyh000011112222@gmail.com> 2016 */
-#include <stdio.h>
-#include <inttypes.h>
 #include <string.h>
 #include <ctype.h>
 #include <errno.h>
diff --git a/include/capstone/platform.h b/include/capstone/platform.h
index 7455b8a..beca8e8 100644
--- a/include/capstone/platform.h
+++ b/include/capstone/platform.h
@@ -95,6 +95,11 @@
 #define PRIX32        "X"
 #endif  // defined(_MSC_VER) && _MSC_VER <= 1700
 
+#if defined(_MSC_VER) && _MSC_VER <= 1700
+// redefine functions from inttypes.h used in cstool
+#define strtoull _strtoui64
+#endif
+
 #define PRId64        __PRI_64_LENGTH_MODIFIER__ "d"
 #define PRIi64        __PRI_64_LENGTH_MODIFIER__ "i"
 #define PRIo64        __PRI_64_LENGTH_MODIFIER__ "o"