Fail when renaming file leads to overwrite

[GregPK]

The part you want to Enhancement
If I have two files foo and bar in the same directory, renaming foo to bar should not be allowed. Should either prevent this with a message, or ask for confirmation.

Why it is necessary to enhancement
While I assume that spf uses mv and this is not a bug, I did not expect it to silently overwrite files when renaming. This expectation if probably due to other UI file browsers actually prevent this:

• pcmanfm - error
• ranger - error
• nnn - confirmation

Additional context
II lost two files because the same name was harder to spot than the example above (lots of files + name were timestamps). Had backups.