Update to 5.509, drop EL-5 support
    
    - New upstream release 5.509
      - Makefile.PL failed with no '.' in @INC (CPAN RT#120871)
      - Test t/Ref.t failed on Windows install (CPAN RT#118262)
      - MIME::Parser::parse_data() should check what it gets back (CPAN RT#119166)
      - Allow \r\n to be used as line-end delimiter when outputting MIME message
        (CPAN RT#119568)
    - Drop EL-5 support (should have happened years ago, dependencies not available)
      - Drop BuildRoot: and Group: tags
      - Drop explicit buildroot cleaning in %install section
      - Drop explicit %clean section