Attempt to use a valid Ruby Module name in Rakefile

I discovered this bug when I added cedar to one of my projects and created a target named "AppName specs", and the resulting `Rakefile` looked something like

```
module AppName specs 
  SPECS_TARGET_NAME = "AppName specs"
  ... et cetera ... 
end
```

I've tried to only replace the instances of `___PACKAGENAME___` with `___PACKAGENAMEASIDENTIFIER___` when it would refer to the module, not to the actual target, or any generated directories.

NB: This still won't work if your spec target starts with anything but a capital letter, but it will support targets with spaces, as well as unicode.

Oh, and for what it's worth, I found out about this template variable [here](https://sites.google.com/site/avrxinu/project-definition/xcode-4-0-templates), but I'm open to another approach to fixing this. Maybe the module name doesn't need to be dynamically based on the target name?