tighter URL management for folder mapping

[davidnuescheler]

in cases where there is a specific spreadsheet with metadata is used for folder mapping only paths that are listed explicitly in the spreadsheet should yield a 200 all other URLs should respond with a 404

[alexcarol]

in cases where there is a specific spreadsheet with metadata is used for folder mapping only paths that are listed explicitly in the spreadsheet should yield a 200 all other URLs should respond with a 404

This would definitely have come in handy for the SAP project, where there's a pretty advanced "versioning" system.