[development] image node type

[Rowan Kerr]

A brief thought:
You could keep "nodes" and "files" separate...

Where nodes are any kind of actual content that is typed into the site
And files are anything that is uploaded by the user

Then you'd have node types and file types.. that could decide just
how to display different things.

nodes would be stuff like: blog, page, article, book page, etc...
files would be stuff like: document, image, spreadsheet, movie, audio...

Because files that are uploaded, I would not really expect should be
given a normal title, body, published/unpublished, etc... that nodes
(actual _content_) would have. Really, node's don't have a filename,
file size, mime type, filesystem path, etc...

Then you get into more of a document management system where
things are clearly defined instead of combining content and external
files under one container.

-Rowan