Use g_timeout_add_seconds() for power efficiency

This attempts to align second-granularity wakeups across the system,
reducing CPU wakeups a little.

I considered all timeouts of duration 1 second or greater, and moved
the non-timing-critical ones to g_timeout_add_seconds(). (Actually,
I didn't find any that I felt were timing-critical)

src/sugar/acme-volume-alsa.c

@@ -292,7 +292,7 @@ bail:
 static void
 acme_volume_alsa_close (AcmeVolumeAlsa *self)
 {
-	self->_priv->timer_id = g_timeout_add (4000,
+	self->_priv->timer_id = g_timeout_add_seconds (4,
 			(GSourceFunc) acme_volume_alsa_close_real, self);
 }