Add Mirage Cask

This commit adds a cask for Mirage 1.0.1.

The `url` and `homepage` fields point to Softpedia as the [original
developer's website](http://www.itaiferber.com) is no longer available.

The description of the application on Softpedia's website reads:

```markdown
Mirage is a free Cocoa based application which will make your dock,
separator, indicator and even Stacks totally clear.

Mirage will allow you to:

- Install a clear dock.
- Install a clear separator.
- Install clear indicators.
- Install clear stacks.
- Restore any combination of those straight from default.
```

Casks/mirage.rb

@@ -0,0 +1,7 @@
+class Mirage < Cask
+  url 'http://download2us.softpedia.com/dl/a52298e7716cfbb6a9949a91cadc8ccd/51ec53d1/400074508/mac/Desktop/Mirage.zip'
+  homepage 'http://mac.softpedia.com/get/Wallpapers/Ferber-Mirage.shtml'
+  version '1.0.1'
+  no_checksum
+  link 'Mirage.app'
+end