EiffelStudio Homebrew package.

I've been told to do a PR here although I'm not sure how this would work for end users to get eiffelstudio without fidling with the homebrew configuration.

Thanks,
Manu
Okay, our preference is to let users build from source on their platform unless it's not supported at all (e.g. it doesn't work). Do oyu mean that it's not actually supported by the buildsystem, or just that the formula isn't set up for it?

If it's the former, then this needs a dependency to indicate that it needs x86-64:

```ruby
depends_on :arch => :x86_64
```