Renamed 'meta' to 'file'
Added list implementation to sort, filter and limit arrays
Removed parent/child relations from items
Added previous and next properties to lists
Reading lists from options and passing them to renderer
Removed item-linker since it's replaced with lists
Various small improvements

- Resolving paths in list filter
- Adding all dates to items in a "dates" object
- Adding "root" property to all "file" objects
- Improved logging
Changed item structure documentation in README according to refactorings
Fixed file references

- file.root and file.path return relative paths to the current document
- moved list.previous/next to list.nav.previous and list.nav.next

E.g. The relative path to the next file in a list can be retrieved via:
{{{listName.next.file.path}}}

To link to resources relatively that live in the root, use:
{{{file.root}}}/css/styles.css
Documentation improvements

- Added links to used projects and technologies
- More detailed usage information
- Credits