[Files] Empty folders ignored unless &include_folders
[Files] Empty folders ignored unless &include_folders

- add() without &include_folders will not add folders themselves to the
list of files.
- Prevents empty folders from being creating in File.sync_from().

Plasmaworks/Rogue,AbePralle/Rogue,AbePralle/Rogue,Plasmaworks/Rogue,Plasmaworks/Rogue,Plasmaworks/Rogue