Collect metadata in .gone directory

[fxnn]

Does it make sense to splatter metadata around in the content root in a dozen files and directories prefixed with .?

Maybe we should think about introducing a single .gone directory, which is never delivered by default (so you can change that via configuration), and which contains stuff like

• htaccess
• templates
• later possibly config
• later possibly index

(Created as followup from #15)