Document Mac OS X configure usage with Homebrew pkg-config path

README

@@ -100,6 +100,11 @@ Basic *nix build instructions:
 ./configure     # NOT needed if autogen.sh used
 make
 
+On Mac OS X, you can use Homebrew to install the dependency libraries. When you
+are ready to build BFGMiner, you may need to point the configure script at one
+or more pkg-config paths. For example:
+	./configure PKG_CONFIG_PATH=/usr/local/opt/curl/lib/pkgconfig
+
 Native WIN32 build instructions: see windows-build.txt
 
 If you build BFGMiner from source, it is recommended that you run it from the