Revert "Wrote _getInterpretation() more efficiently."
These changes introduced a number of bugs.
The whole idea of explicitly stating "studentID" versus "givenID"
is a good one, but it needs some work.

This reverts commit 4d30f4d8847ffa6b336a1f934b84db8f859f31d5.
Add submodes as choice in login.html
Add directives to enable/disable individual
options in a select control.  As an example, for
all but power and TEST, deselect "Function" as a choice for type.
Wire up descriptions and type control handlers to message box.