Lots of formatting fixes for Adobe Reader Cask; Added Zap method

Trying to simplify updating the Adobe Reader Cask by automatically determining the version number in download URL

Also added "zap" method for Adobe Reader => "Adobe Reader.app" is now deleted after uninstalling. (It was left there before, but could not be started)

Also, might it be possible to implement something like "version.to_roman" in homebrew-cask, which would result in "XI" for version 11? Adobe uses a lot of roman numbering for their products. I think having a method like this would help simplifying the update process :)