Add readme for mac

Source/WXDialog/ReadMe.Mac.txt

+Hi All,
+
+So, here is a short description on how I got installation package on mac osx.
+
+1. Build package.
+2. Copy package and related files to the following directory structure:
+
+./Package_Root/Applications/MyApp.app/Contents/Info.plist
+./Package_Root/Applications/MyApp.app/Contents/MacOS
+./Package_Root/Applications/MyApp.app/Contents/MacOS/MyAppExec
+./Package_Root/Applications/MyApp.app/Contents/PkgInfo
+./Package_Root/Applications/MyApp.app/Contents/Resources/MyAppIcon.icns
+./Package_Root/Applications/MyApp.app/Contents/Resources/MyAppResources.rsrc
+./Package_Root/usr/share/somedata
+./Package_Root/usr/bin/some_utility
+./Resources/License.txt
+./Resources/ReadMe.txt
+./Resources/Welcome.txt
+
+The file PkgInfo contains "APPL????"  The file Info.plist contains
+package instructions. I would suggest looking at Info.plist.in in
+wxWindows and modify it by putting your info in.  MyAppIcon.icns is an
+icon created by IconComposer in /Developmer/Applications.
+MyAppResources.rsrc is a compiled resources file. I used the one from
+wxWindows and it seems to be working fine. Some mac person could
+explain this. Make sure that Info.plist contains:
+
+        <key>CFBundleIconFile</key>
+        <string>MyAppIcon.icns</string>
+
+This will tell it which icon to use.
+
+The ./Package_Root/usr/share/somedata and
+./Package_Root/usr/bin/some_utility are some extra data that your
+application is using. For example they can be a command line version
+of the application and some common files. 
+
+The ./Resources directory contains resources used during
+installation. The names of files describe what should go in. They can
+be rtf, txt...
+
+3. Create package using PackageMaker. 
+
+Fire up PackageMaker from /Developmer/Applications. Fill all the
+entries. Most of them are straight forward. Package root is
+./Package_Root. Resources directory is ./Resources. If your
+application needs to write to /usr (or to some other place beside
+/Applications, then make sure to enable authentication. After you fill
+all the entries, create package. This will create a directory on your
+disk containing a whole lot of junk. Now you need to package this
+directory.
+
+4. Create a disk image.
+
+Run Disk Copy from /Applications/Utilities. The easiest way of
+creating disk image is to first create empty folder, copy all the
+files in and then tell Disk Copy to create disk image from folder. So,
+create folder MyApp, copy in MyApp.pkg and create package.
+
+Now you are done. This will create one file, which you can copy around.
+
+So, what is missing is how to make application icon show in the
+finder. I can make it show when running application, but not when I am
+looking at application. Even if I ask for preview.
+
+I guess somebody else will have to answer this.
+
+Good luck.
+
+                        Andy
+