Add username as an available field

[mackensen]

This has been discussed on the Moodle Plugins Directory so I'm bringing the discussion here. The request is to display the username in addition to the fullname. This requires two changes:

• The user_picture() function call needs the username passed as an extra field.
• The username has to be outputted in a second span.

I'm going to push some code up as an example but to make it into a release this behavior would need to be controlled somehow.

[andyzito]

This has been implemented.