Builder|OS X: Package apps as additionally as plain ZIPs

OS X apps can be distributed as-is, so this is the simplest way to
install Doomsday or Doomsday Shell. Both apps are still signed.

distrib/platform_release.py

@@ -270,6 +270,10 @@ def fw_codesign(app):
     print 'Signing Doomsday Shell.app...'
     codesign("Doomsday Shell.app")
 
+    print 'Packaging apps as individual ZIPs...'
+    os.system('zip -9 -r -q "../releases/doomsday_osx_%s.zip" "Doomsday Engine.app"' % DOOMSDAY_VERSION_FULL)
+    os.system('zip -9 -r -q "../releases/doomsday_shell_osx_%s.zip" "Doomsday Shell.app"' % DOOMSDAY_VERSION_FULL)
+
     print 'Creating disk:', target
     os.system('osascript /Users/jaakko/Dropbox/Doomsday/package-installer.applescript')