Add support for modules containing directories
Let apply perform installation and syncing

+ Move default files into modules/base
+ Add configuration in `target`
Make manifests pr. module
Let the world know!
Remove partly-useless error message
Remove specific configuration
Add dry-run and abstract logging
Add manifest generation/signing into apply script
Rename 'apply' to 'gone'
More consistent API
Use message as default verbosity level
Remove unused spec
Re-add integrity check to 'apply'
Add --target option to specify config target
Add configurable sync agents
Fix integrity check performed previously
Remove wrong comments
Update the docs
Add default configuration target
Add example to use pr. host modules