Update to 1.27
--------------
1.27  2015-09-06
- readline-7.0 support
    new function
rl_callback_sigcleanup
- improve POD documents
- Gnu.xs: not to use obsoleted typedefs which were obsoleted
          by ReadLine 6.3
- fix a wrong fix on 1.21 to let completion_function do case
          insensitive match. [rt.cpan.org #72378]
- fix rl_display_match_list to show the first entry of the
          array.  The bug caused segmentation fault with readline-7.0.
- some improvement of Makefile.PL:
  - add support homebrew on Mac OS X. [rt.cpan.org #104389]
  - print an error string when system() fails.
  - specify 'int' on 'main()'.
  - use -O when -D_FORTIFY_SOURCE is defined.

(mef)