Recent updates in storage (#667)

* Fix error handling in Torrent.cpp, improve choosing peers for upload

* Various improvements in storage daemon

"get-pieces-info"
Store "added at"
Improve calculating up/down speed
Improve TL protocol for future compatibility
Remove empty directories on "--remove-files"
Better windows support
Debug logs in PeerActor
More restrictions on TorrentInfo
Bugfixes

* Global speed limits for download and upload

+bugfix

* Reset download/upload speed on changing settings or completion

* Exclude some system files in TorrentCreator

storage/TorrentInfo.cpp

@@ -73,6 +73,12 @@ td::Status TorrentInfo::validate() const {
   if (description.size() > 1024) {
     return td::Status::Error("Description is too long");
   }
+  if (piece_size > (1 << 23)) {
+    return td::Status::Error("Piece size is too big");
+  }
+  if (pieces_count() >= (1ULL << 31)) {
+    return td::Status::Error("Too many pieces");
+  }
   return td::Status::OK();
 }
 }  // namespace ton