Andrew Nicols ce1c470167 MDL-66841 forum: Display grade update errors to user
Part of MDL-66074

This change modifies the return val for all of the grading functions to
allow them to add additional information.
This means that a grading service can suppress a Grade saved message if
there were no changes, for example.

This also adds a distinction between:
- Errored (Exception thrown in the WS call)
- Failed (Warning in the output of the WS call)
- Success (Grade actually saved)
- None of the above (No save, no fail, no change)
2019-10-30 10:23:41 +08:00
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2019-10-30 10:23:40 +08:00
2013-01-14 15:14:54 +11:00