JTec beads provides small set of core objects which are suitable
to manage and reuse even most complicated content.
Storage area for beads. It is organised like file system
(and actually backed by it). Indivudual beads are adressed by means
of java.io.File name.
Bead is individual piece of content identified by its file name and
stored in canvas (this name is valid only in context of given canvas,
and is not quaranted to be related to real file system name). Bead is
storage container to some form of content.
Actual content is stored inside of content objects assitoated with bead.
Conent does not exist standalone. Different types of content are available.
Attributed objects ( beads and their content ) can store arbitrary
attributes of any data type serialisable by xstream