- Fixed overflow that caused ratio to become negative

- Added some more asserts so that it doesn't happen again
- Fixed waiting for paused_alert on exit in the case where a torrent was paused then resumed before we received torrent_paused_alert

src/properties_imp.cpp

@@ -93,7 +93,7 @@ properties::properties(QWidget *parent, bittorrent *BTSession, torrent_handle &h
     else
       ratio = 10.; // Max ratio
   }else{
-    ratio = (float)torrentStatus.total_payload_upload/(float)torrentStatus.total_payload_download;
+    ratio = (double)torrentStatus.total_payload_upload/(double)torrentStatus.total_payload_download;
     if(ratio > 10.){
       ratio = 10.;
     }