Closed beta 10019010: unified attach button, new intro, new stickers.

Now all files sending is confirmed before preparing for sending.
You can paste from clipboard and drag many files at once.

Telegram/SourceFiles/boxes/stickers_box.cpp

@@ -265,7 +265,7 @@ void StickersBox::setup() {
 
 	rebuildList();
 
-	prepare();
+	raiseShadow();
 }
 
 void StickersBox::refreshTabs() {