Merge fiix compilation on newer versions of Mac OS X (Lion and up). Thanks Ryan McKern.

NEWS

@@ -8,6 +8,8 @@
 
   * Fix use of SubprocessWrapper on Windows. (Paulo Madeira, #670035)
 
+  * Fix compilation on newer versions of Mac OS X (Lion and up). (Ryan McKern, #794543)
+
 0.7.1	2011-04-12
 
  BUG FIXES

dulwich/_objects.c

@@ -25,7 +25,7 @@
 typedef int Py_ssize_t;
 #endif
 
-#if defined(__MINGW32_VERSION) || defined(__APPLE__)
+#if defined(__MINGW32_VERSION) || (defined(__APPLE__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 1070)
 size_t strnlen(char *text, size_t maxlen)
 {
 	const char *last = memchr(text, '\0', maxlen);