cache: add a way to explicitly resume cache

stream/cache.c

@@ -373,6 +373,10 @@ static int cache_get_cached_control(stream_t *cache, int cmd, void *arg)
         }
         return STREAM_UNSUPPORTED;
     }
+    case STREAM_CTRL_RESUME_CACHE:
+        s->idle = s->eof = false;
+        pthread_cond_signal(&s->wakeup);
+        return STREAM_OK;
     }
     return STREAM_ERROR;
 }

stream/stream.h

@@ -93,6 +93,7 @@ enum stream_ctrl {
     STREAM_CTRL_GET_CACHE_SIZE,
     STREAM_CTRL_GET_CACHE_FILL,
     STREAM_CTRL_GET_CACHE_IDLE,
+    STREAM_CTRL_RESUME_CACHE,
     STREAM_CTRL_RECONNECT,
     // DVD/Bluray, signal general support for GET_CURRENT_TIME etc.
     STREAM_CTRL_MANAGES_TIMELINE,