def file(name)
      files.find {|file| file.file_ref.name == name or file.file_ref.path == name  }
    end
def file(name)
      files.find {|file| file.file_ref.name == name or file.file_ref.path == name  }
    end
Return the BuildFile given the file name.

 @param [String] name of the FileReference that is being built.
 @return [BuildFile] the BuildFile that links to the file specified with
   the name.