Fix bug: No OSD until valid video stream shown.

ChangeLog

@@ -1,6 +1,8 @@
 User johns
 Date:
 
+    Wakeup display thread on channel switch, osd can now be shown without
+    video.
     Makes 60Hz display mode configurable with setup.conf.
     Support downmix of AC-3 to stero.
     New audio PES packet parser.

Todo

@@ -37,7 +37,6 @@ video:
     reduce warnings after channel switch
     grab image with hardware and better scaling support
     hard channel switch
-    OSD can only be shown after some stream could be shown
     yaepghd changed position is lost on channel switch
     pause (live tv) has sometime problems with SAT1 HD Pro7 HD
 
@@ -77,7 +76,6 @@ x11:
     support embedded mode
 
 audio:
-    write TS -> PES parser, which feeds audio before the next start packet
     Combine alsa+oss ringbuffer code.
     Make alsa thread/polled and oss thread/polled output module runtime
     selectable.

softhddev.c

@@ -1834,6 +1834,7 @@ void SetPlayMode(void)
 	return;
     }
     Resume();
+    VideoDisplayWakeup();
     if (MyVideoDecoder) {
 	if (VideoCodecID != CODEC_ID_NONE) {
 	    NewVideoStream = 1;