Fixing warnings. Added JSONCPP_DEPRECATED definition for clang. Also updating .gitignore to ignore .DS_Store files (Mac OS Finder generated)
diff --git a/include/json/config.h b/include/json/config.h
index b2bfb29..c83e78a 100644
--- a/include/json/config.h
+++ b/include/json/config.h
@@ -120,6 +120,9 @@
 #endif
 
 #ifdef __clang__
+#  if __has_extension(attribute_deprecated_with_message)
+#    define JSONCPP_DEPRECATED(message)  __attribute__ ((deprecated(message)))
+#  endif
 #elif defined __GNUC__ // not clang (gcc comes later since clang emulates gcc)
 #  if (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5))
 #    define JSONCPP_DEPRECATED(message)  __attribute__ ((deprecated(message)))