Removed unnecessary fields from skill_trainer.cpp in SHL_Skill_Trainer. Updated train.php web interface to fix a bug that incorrectly had a div nested too far down to be displayed on menu-change.

Lots of changes to how Task Graphs are done. Rewrote CTG->TH, TH->CTG transformation functions for RSS paper. Added more helper functions to Graph and Node base classes for looking up in/outbound edges (and assoc. nodes) for a graph's nodes.