CourseCreator: Quote escape first/last names.

Encountered a case where a student had a comma in their name. So now
first and last names are double quote escaped when generating the
classlist file.
Classlist parsing using Text::CSV.

The Text::CSV library allows using double quotes to escape values that
might contain a comma.

Also added provision to assume that all classlist files are UTF8.
This allows names that have non-ASCII characters to be rendered
correctly in Webwork.