Modifications in these two files make questions whose answer blanks hve
the same names behave properly.
The new versions of CGI seem to return such answers as a reference to an array.
Earlier versions returned the answrs as a string with \0 separators.
With the new changes the AnswerEvaluator get_student_answer subroutine and
the NAMED_ANS_RULE in PGbasicmacros.pl will handle either a null separated
string or an answer array when dealing with vector answers.
This should correct some difficulties experienced in the linear algebra
questions. More testing needs to be done.