Give plugins the ability to talk

Finally, some sort of built-in TTS support.  When a plugin emits a "tts"
signal, the Kaylee object will receive it and speak the given text
aloud.  It even stops listening while it speaks to prevent Kaylee from
talking to herself.  If no TTS is configured, it will print the text
instead, but since a default TTS setting is provided in the new
options.json.tmp, that shouldn't happen much.

Currently there's no way for the shell plugin to use TTS.  The D-Bus
interface will change that once I get around to making it.  Speaking of
D-Bus, UIs are broken again and I'm sure I can fix them once they're
separate processes talking to Kaylee by D-Bus.

kayleevc/kaylee.py

         for plugin in self.plugins:
             self.recognizer.connect('finished', plugin.recognizer_finished)
             plugin.connect('processed', self.plugin_processed)
+            plugin.connect('tts', self.plugin_tts)
         self.recognizer.connect('finished', self.recognizer_finished)
 
     def update_voice_commands_if_changed(self):
         print("no matching command {0}".format(text))
         self._stop_ui(text)
 
+    def plugin_tts(self, plugin, text):
+        # Stop listening
+        self.recognizer.pause()
+        # Speak
+        try:
+            subprocess.call(self.options['tts'] + [text])
+        except KeyError:
+            print('TTS:', text)
+        # Resume listening
+        self.recognizer.listen()
+
     def _stop_ui(self, text):
         # If there is a UI and we are not continuous listen
         if self.ui:

kayleevc/plugins/pluginbase.py

 
     __gsignals__ = {
         'processed' : (GObject.SIGNAL_RUN_LAST, GObject.TYPE_NONE,
-                      (GObject.TYPE_STRING,))
+                      (GObject.TYPE_STRING,)),
+        'tts' : (GObject.SIGNAL_RUN_LAST, GObject.TYPE_NONE,
+                (GObject.TYPE_STRING,))
     }
 
     def __init__(self, config, name):

kayleevc/plugins/simple.py

         if text == self.options['phrase']:
             self.emit('processed', text)
             print("Simple plugin says:", text)
+            self.emit('tts', text)
             return True
         else:
             return False

options.json.tmp

     "microphone": null,
     "interface": null,
     "valid_sentence_command": null,
-    "invalid_sentence_command": null
+    "invalid_sentence_command": null,
+    "tts": ["espeak", "-ven-us+f2"]
 }