Mac OS X post-install

[afb]

Going to add a post-install to the main codeblocks program for wxMac,
so that it adds the icon and resource fork and make it receive events...

It runs two commands: /Developer/Tools/Rez and /Developer/Tools/SetFile,
and these will be defined as "@true" for the other wxWidgets platforms.

You can still add bundling afterwards (in fact this is the recommended way),
but adding the resource fork is very handling when debugging for instance.

See also http://forums.next.codeblocks.org/index.php?topic=4385.0