Namespace backup/swap files by filename
Namespace backup/swap files by filename

Currently, backup/swap of files with the same name will overwrite each other.
This triggers a built-in namespacing feature for this use case.

From vim help:

> For Unix and Win32, if a directory ends in two path separators,
> the swap file name will be built from the complete path to the file
> with all path separators substituted to percent '%' signs.
> This will ensure file name uniqueness in the preserve directory.

tantion/vim,tantion/vim