[client] spice: own transport configuration

Register SPICE connection and component options in the SPICE transport.
Move generic input and clipboard settings out of the SPICE namespace,
while retaining migration aliases for existing configurations.

Keep PureSpice and usbredir build requirements private to the transport,
and remove obsolete SPICE configuration state from the client core.

client/transports/SPICE/spice.c

@@ -36,6 +36,65 @@ static void spiceDisconnect(LG_Transport * transport);
 
 static void spiceSetup(void)
 {
+  static struct Option options[] =
+  {
+    {
+      .module         = "spice",
+      .name           = "enable",
+      .description    = "Enable the built-in SPICE transport",
+      .shortopt       = 's',
+      .type           = OPTION_TYPE_BOOL,
+      .value.x_bool   = true
+    },
+    {
+      .module         = "spice",
+      .name           = "host",
+      .description    = "The SPICE server host or UNIX socket",
+      .shortopt       = 'c',
+      .type           = OPTION_TYPE_STRING,
+      .value.x_string = "127.0.0.1"
+    },
+    {
+      .module         = "spice",
+      .name           = "port",
+      .description    = "The SPICE server port (0 = unix socket)",
+      .shortopt       = 'p',
+      .type           = OPTION_TYPE_INT,
+      .value.x_int    = 5900
+    },
+    {
+      .module       = "spice",
+      .name         = "input",
+      .description  = "Enable SPICE keyboard and mouse input",
+      .type         = OPTION_TYPE_BOOL,
+      .value.x_bool = true
+    },
+    {
+      .module       = "spice",
+      .name         = "clipboard",
+      .description  = "Enable SPICE clipboard synchronization",
+      .type         = OPTION_TYPE_BOOL,
+      .value.x_bool = true
+    },
+    {
+      .module       = "spice",
+      .name         = "audio",
+      .description  = "Enable SPICE audio support",
+      .type         = OPTION_TYPE_BOOL,
+      .value.x_bool = true
+    },
+    {
+      .module       = "spice",
+      .name         = "usbAudio",
+      .description  = "Use USB redirection for SPICE audio playback",
+      .type         = OPTION_TYPE_BOOL,
+      .value.x_bool = false
+    },
+    {0}
+  };
+
+  option_register(options);
+
   const PSInit init =
   {
     .log =
@@ -60,12 +119,20 @@ static bool spiceCreate(LG_Transport ** result)
   transport->host             = option_get_string("spice", "host");
   transport->port             = option_get_int("spice", "port");
   transport->inputEnabled     = option_get_bool("spice", "input");
-  transport->clipboardEnabled = option_get_bool("spice", "clipboard");
+  transport->clipboardEnabled =
+    option_get_bool("spice", "clipboard") &&
+    (option_get_bool("clipboard", "toVM") ||
+      option_get_bool("clipboard", "toLocal"));
   transport->audioEnabled     = option_get_bool("spice", "audio");
   transport->usbAudioEnabled  =
     option_get_bool("spice", "usbAudio");
   transport->audioDebug       = option_get_bool("audio", "debug");
 
+#if !ENABLE_USB_AUDIO
+  if (transport->audioEnabled && transport->usbAudioEnabled)
+    DEBUG_WARN("USB audio is unavailable in this build, using SPICE audio");
+#endif
+
 #if ENABLE_AUDIO
   transport->playbackEnabled =
     transport->audioEnabled && lgAudio_supportsPlayback();