code: def unique_paths_for(name, opts = {})
        tally = {}
        output = []
        paths_for(name, opts).reverse.each do |ary|
          tally[ary[1]] ||= ary[0]
          output << ary if tally[ary[1]] == ary[0]
        end
        output.reverse
      end
docs: Provides an expanded, globbed list of paths and files for a given name.
   The result includes only the last matched file of a given sub path and name.
  
   @param        [Symbol]    name    The name of the paths group
   @param        [Hash]      opts    An options hash
   @option opts  [Boolean]   :invert (false) Inverts the order of returned paths and files
  
   @example
     #Given the following:
     #  /path/one/file1.rb
     #  /path/one/file2.rb
     #  /path/two/file1.rb
  
       MyClass.push_path(:files, ["/path/one", "/path/two"], "**/*.rb")
  
     MyClass.unique_paths_for(:files)
     MyClass.unique_paths_for(:files, :invert => true)
  
   @return [Array]
     Returns an array of [path, file] arrays
     Results are retuned in declared order.  Only unique files are returned (the file part - the path)
     In the above example, the following would be returned for the standard call
       [
         ["#{root}/path/one", "/file2.rb"],
         ["#{root}/path/two", "/file1.rb"]
       ]
     For the inverted example the following is returned:
       [
         ["#{root}/path/one/file2.rb"],
         ["#{root}/path/one/file1.rb"]
       ]
  
   @api public
   @since 0.1.1
   @author Daniel Neighman