Add Overwrite option

Hello, first of all, thanks for this good tool !
For me, it missing "Overwriting option" like Filezilla :

Overwrite if source newer
Overwrite if different size
Overwrite if source newer or different size

Thanks

There's Newer only option:
https://winscp.net/eng/docs/ui_overwrite

For the "size" option, you can use synchronization or "directory compare".