[gtk+] Drop outdated files

[Matthias Clasen <matthiasc src gnome org>]

commit cc141329edd14f001f42da7cd4a025077c72ccca
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Sep 21 22:48:26 2014 -0400

    Drop outdated files
    
    These files stem from the time when the documentation was in
    a separate module - long, long ago.

 docs/reference/AUTHORS            |    7 ----
 docs/reference/COPYING            |   30 ------------------
 docs/reference/README             |   62 -------------------------------------
 docs/reference/README.cvs-commits |   39 -----------------------
 4 files changed, 0 insertions(+), 138 deletions(-)