Continue with VisTrails Planning

- Minor revisions to the "Planning Meeting" document.
- Added SVG files for trial queries 2 through 10.
- Trial queries 5 and 9 are still unplanned.
Modify Indexer and IndexedPiece

- removed references to "Experiment" in IndexedPiece
- added settings functionality to Indexer
- other small things... still a work in progress
Added Experimental MultiProcessingController

The idea is that it will take arbitrary work from arbitrary places,
complete it, and return it to arbitrary places. This way, hopefully it'll
be much easier to write modules that use multiprocessing.