The `about_file_path` for the "usual" input for `gen` should be `about_resource_path`

[chinyeungli]

The current design is to name the Resource column as about_file_path and the the tool will generate the corresponding .ABOUT file next to the resource.
However, the "real" meaning for the "Resource" should be about_resource_path instead of about_file_path.

[pombredanne]

The code has changed since and this ticket is now invalid.