Add helper function to get a set of all of the Stmt children of a Stmt.
Log debug messages for failed calls to raiseMovementEvent().
Add functions to move a thread until a Stmt has next finished evaluated, or had
previously finished evaluating.
Allow users to right-click on Stmts in the source code viewer, giving them a
context menu with options to move the state based on the Stmt (currently,
either to the next point where the Stmt has been evaluated, or to the previous
point where the Stmt had been evaluated).