[tomboy] Remove surplus files

[Alex Tereschenko <alexter src gnome org>]

commit ad3d8e8062716aa7196e7e5a8e50331a5a289dfd
Author: Alex Tereschenko <frozen and blue gmail com>
Date:   Sun Aug 28 20:51:00 2016 +0200

    Remove surplus files
    
    Changelog.pre-git is actually empty and unused,
    MAINTAINERS is long not used by GNOME infrastructure,
    DOAP file is used instead.

 ChangeLog.pre-git |    4 ----
 MAINTAINERS       |   27 ---------------------------
 2 files changed, 0 insertions(+), 31 deletions(-)