unify presentation of hashed and named stuff
rename named-folders to named-objects to better reflect the unification
introduce a general handler for file content
fix the stupid mistakes
reorganise source code

* move image related stuff in a separate file
* group the code by its function
* add some documentation
scripting with jquery and parenscript
define a number of classes representing the nodes of the document graph
access to stream elements by index or hash or name
introduce an interface for objects with parents
build a storage backend with hash-tables
begin migration to web-utils
try developing some analogue of presentations