Adds a set of options to the essay question type which implement
the following new features:
-Adds an input format which accepts only file uploads, and no
inline text.
-Adds an option to make the inline text response optional when
attachments are enabled, so students can choose to upload
an essay file.
-Adds an option to make attachments required, so essays without
attachments will be marked incomplete.
The problem was with the non-UTF-8-safe way that a question name
was being constructed from the question text.
I have done a proper fix with methods in the base class to
carefully construct a question name that is reasonable, and
which will fit in the database column. Then I have changed all
importers to use the new methods.
I also remembered not to break the lesson in the process.
Jean-Michel Vedrine