Log Message: 
Created the first draft of the Parser's function answer checker. Some
work still needs to be done, in particular, type mismatches are not
being reported, and lists are being processed only as ordered lists
with no partial credit.
This doesn't implement everything from fun_cmp. In particular, there
is no support for parameter matching at the moment. This will have to
be added, but I'm not quite sure how to do it when the function's
return value is not a real number (e.g., an interval).
On the other hand, this checker is more forgiving about domain errors:
if tries a point where the professor's function is not defined, it
ignores that one and looks for another (until it decides it can't find
one). Once it has these points, it tries them on the student's
answer, and if the student's function is undefined, then the student
answer is wrong (since it is not defined somewhere that the
professor's funciton is). This avoids the "Error evaluating student
function at ..." messages, which just confused most students anyway.
