Remove redundant Item#initialize documentation
Remove binary-ness from item reps (it depends on the snapshot anyway)
Create Content class for storing textual and binary data
Let binary content expect the file to exist
Fix path calculation in less filter
Fix passing of content in rendering helper
Make content filenames absolute
Simplify path matching in sass filter
Remove outdated TODO
Fix incorrect documentation for ItemRep#content
Merge branch '4.0-content-object'