daemon-conf: disable flat-volumes by default

Almost all distributions patch the configuration to disable
flat-volumes, because users tend to find the concept confusing (and it
also causes nasty surprises when some application pushes the volume to
100%). Let's remove the need for patching and disable the feature by
default.

Fixes: https://gitlab.freedesktop.org/pulseaudio/pulseaudio/issues/691

man/pulse-daemon.conf.5.xml.in

@@ -237,7 +237,7 @@ License along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
       <p><opt>flat-volumes=</opt> Enable 'flat' volumes, i.e. where
       possible let the sink volume equal the maximum of the volumes of
       the inputs connected to it. Takes a boolean argument, defaults
-      to <opt>yes</opt>.</p>
+      to <opt>no</opt>.</p>
     </option>
 
   </section>

src/daemon/daemon-conf.c

@@ -68,7 +68,7 @@ static const pa_daemon_conf default_conf = {
     .realtime_priority = 5,  /* Half of JACK's default rtprio */
     .disallow_module_loading = false,
     .disallow_exit = false,
-    .flat_volumes = true,
+    .flat_volumes = false,
     .exit_idle_time = 20,
     .scache_idle_time = 20,
     .script_commands = NULL,

src/daemon/daemon.conf.in

@@ -60,7 +60,7 @@ ifelse(@HAVE_DBUS@, 1, [dnl
 ; enable-lfe-remixing = no
 ; lfe-crossover-freq = 0
 
-; flat-volumes = yes
+; flat-volumes = no
 
 ifelse(@HAVE_SYS_RESOURCE_H@, 1, [dnl
 ; rlimit-fsize = -1