Attempted port update solution where update occurred only
after mouseup. But this runs into immediate problems.
Simply dragging a penultimate segment can cause the port to
change sides, and we are now failing to handle this properly.
Problem seems to be fixed....
Switched off diagnostic output.
trying to fix problem with even BPSC collapse.
Seems we just forgot one final Edge.redraw after port updates.
turned off diagnostic output
switching to real tasks in tasks.php
Added new graphs
writing remaining questionnaire pages etc.
added recordData2.php
Made left pane scrollable.
puts drags and atoms into one single sequence of events
made data recorded in write-only files; also put letterhead on exp_statement.pdf
fixed problems with css
Working on UNDO/REDO...
Made key up not turn off ctrl or shift unless it was actually
one of those keys being released.
Added howto page on undo/redo.
minor: changes graphs, added text on web pages...
reinstated edge highlighting