image now allows two different values for image url

image = "image.png"
leads to static/20xx/articlename/image.png
to be used for unique lead images

image="/images/name.png"
leads to static/images/name.png
to be used for unique lead images

 - now I understand how it works ;)

metadata: allow override date and author from metadata
format:
[author]
name = "Name"
email = "my@email.com"
[date]
creation = "2015-07-31"

Fixes #1

Fix1

Přidána práva, doplněno README

See merge request !1