This commit also includes a lot of useful tidying up of some of the unit
test helper code. I turned out that I could not use all the helper code
in my new tests, but despite that it will be useful in the future, so I
am committing it here.

Merge branch 'MDL-29089_grade_history_missing_columns2' of git://github.com/andyjdavis/moodle.git (resolved version.php conflicts)

defaults.

At the moment, each message_provider can specify defaults for
each message output, to say whether that message output should be
used for this type of message:
http://docs.moodle.org/dev/Messaging_2.0#Adding_new_message_type.

If the message provider does not set a default, this change allows
the message output to set the default.

Tim Hunt authored Sep 30, 2011 and Eloy Lafuente committed Oct 04, 2011

This is a temporary fix, until the new API from MDL-29589 is available.

(amended to fix comments)

Tim Hunt authored Sep 29, 2011 and Eloy Lafuente committed Oct 04, 2011

This changes the hint that comes before the question text. There are
unit tests to verify the new behaviour.

(amended to fix comments)

Portfolio API code in the assignment module expected that the current
user is the author of the submission. Therefore the "Export to
portfolio" button did not work when the submission was viewed by a
teacher (eg at the page with the list of all submissions in the Advanced
upload assignment).

This patch introduces a new callback argument 'submissionid' that holds
explicit ID of the submission the export deals with. With it available,
we do not need to expect the current user is the author of the
submission.

The patch also cleans some strings used for portfolio callback
exceptions.

When this code was used as a part of the grading screen, the default
PORTFOLIO_ADD_FULL_FORM widget led to nested form elements. This patch replaces
the form widget with a plain text link that can be embedded safely.