[modules/pulsectl] add preliminary version of event-based pulseaudio

add a new module based on pulsectl, with pulsein for microphone and
pulseout for speakers.

should eventually become a drop-in replacement for pasink and pasource.

see #917

themes/icons/ascii.json

@@ -64,6 +64,14 @@
       "prefix": "audio"
     }
   },
+  "pulseout": {
+    "muted": {
+      "prefix": "audio(mute)"
+    },
+    "unmuted": {
+      "prefix": "audio"
+    }
+  },
   "amixer": {
     "muted": {
       "prefix": "audio(mute)"
@@ -80,6 +88,14 @@
       "prefix": "mic"
     }
   },
+  "pulsein": {
+    "muted": {
+      "prefix": "mic(mute)"
+    },
+    "unmuted": {
+      "prefix": "mic"
+    }
+  },
   "nic": {
     "wireless-up": {
       "prefix": "wifi"