Add ChangeLog template.

Change-Id: Ic0dfc0180634b630ac1359298f3d251b3d23e0a7
Reviewed-by: Mitch Curtis <mitch.curtis@digia.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Richard J. Moore <rich@kde.org>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>