def gsub(pat, rep)
      inject(self.class.new) { |res, fn| res << fn.gsub(pat, rep) }
    end
def gsub(pat, rep)
      inject(self.class.new) { |res, fn| res << fn.gsub(pat, rep) }
    end
Return a new FileList with the results of running +gsub+ against each
 element of the original list.

 Example:
   FileList['lib/test/file', 'x/y'].gsub(/\//, "\\")
      => ['lib\\test\\file', 'x\\y']