Major visualization package update. See info:

* Divided the package into 2 parts: definition and implementation.
Definition defines the visualizations tasks, common data structures
(used both internally and externally) and task result types (for nice &
easy integration with calling code).
Implementation contains the original visualization package code.
* Out of the 3 quartz jobs, 1 is now obsolete (made obsolete by the
task definitions mentioned above), the other 2 have been rewritten to
use the new syntax (1 of them only contains commented code though).
* New types have been propagated to original visualization code, as was
needed (seems only type names were changed).
* Definition of comparison task (its result type) is not complete yet
:).