Fixes, mainly for Clang/Mac, from Cinder.

indra/llcommon/fix_macros.h

@@ -0,0 +1,25 @@
+/**
+ * @file   fix_macros.h
+ * @author Nat Goodspeed
+ * @date   2012-11-16
+ * @brief  The Mac system headers seem to #define macros with obnoxiously
+ *         generic names, preventing any library from using those names. We've
+ *         had to fix these in so many places that it's worth making a header
+ *         file to handle it.
+ * 
+ * $LicenseInfo:firstyear=2012&license=viewerlgpl$
+ * Copyright (c) 2012, Linden Research, Inc.
+ * $/LicenseInfo$
+ */
+
+// DON'T use an #include guard: every time we encounter this header, #undef
+// these macros all over again.
+
+// who injects MACROS with such generic names?! Grr.
+#ifdef equivalent
+#undef equivalent
+#endif 
+
+#ifdef check
+#undef check
+#endif