RoomInputToolbarView: Add file upload action.

Riot/Modules/Room/Views/InputToolbar/RoomInputToolbarView.h

@@ -38,6 +38,13 @@ typedef enum : NSUInteger
  */
 - (void)roomInputToolbarViewPresentStickerPicker:(MXKRoomInputToolbarView*)toolbarView;
 
+/**
+ Tells the delegate that the user wants to send external files.
+ 
+ @param toolbarView the room input toolbar view
+ */
+- (void)roomInputToolbarViewDidTapFileUpload:(MXKRoomInputToolbarView*)toolbarView;
+
 @end
 
 /**