Merge topic branch t/deprecate_setatt into next

A single patch which deprecates the setatt server subcommand. This subcommand
fails, for example, if the name of an audio file happens to end in '+'
or '-'. The replacement for setatt are the two new options to the touch
subcommand to set or unset attributes.

* refs/heads/t/deprecate_setatt:
  server: Deprecate setatt in favor of touch.

diff --cc aft.c
Simple merge

diff --cc client.c
Simple merge

diff --cc m4/lls/server_cmd.suite.m4
Simple merge