mac: Update README.mac.txt a bit

README.mac.txt

@@ -1,17 +1,37 @@
 Requirements
 ============
 
-OSX 10.4 or higher
+OSX 10.6 or higher (might also work with 10.5)
 an Intel mac
-xcode
+brew (https://github.com/mxcl/homebrew) or macports (http://www.macports.org/)
+Xcode
+CMake (http://www.cmake.org/)
 
 Build
 =====
 
-Launch xcode and load the project. Select the desired configuration and build.
+-Install dependencies using brew or port (libjpeg, libpng, freetype…)
+-Launch the CMake GUI application
+-Click Browse Source… button, navigate to your openclonk repository folder
+-Also Specify location where you want to build
+-Click Configure and use default native compilers
+-Wait
+-<Potentially include additional steps to make CMake find the right libraries>
+-If you want 64-bit builds, go set the CMAKE_OSX_ARCHITECTURES setting to "x86_64"
+	-For universal builds set it to "x86_64 i386", but then you'll also need universal versions of the dependencies
+-Click Configure button again for good measure
+-Click Generate
+-Launch xcode and load the project. Select the desired configuration and build.
 
 It should be pretty straight forward, hopefully.
 
+Additional CMake hints
+=====================
+
+FREETYPE_LIBRARY should be set to /usr/X11/lib/libfreetype.6.dylib
+ZLIB_LIBRARY to /usr/lib/libz.dylib
+ZLIB_INCLUDE_DIR to /usr/include
+
 NoNetwork
 =========